Contents
1.1 Background
1.2 Purpose of the Manual
1.3 Project Description
1.4 Objectives of the EM&A Programme
1.5 Scope of the EM&A Programme
1.6 Organisation and Structure of the EM&A
1.7 Structure of the EM&A Manual
2.1 Introduction
2.2 Environmental Monitoring
2.3 Action and Limit Levels
2.4 Event and Action Plan
2.5 Enquiries, Complaints, and Requests for Information
2.6 Reporting
2.7 Cessation of EM&A
3.1 Introduction
3.2 Monitoring Activities
3.3 Monitoring for Dredging Activities
3.4 Monitoring for Backfilling Activities
3.5 Monitoring for Capping Activities
3.6 Sampling Procedure for Water Quality Monitoring
3.7 QA/QC
3.8 Data Quality Objectives
4.1 Introduction
4.2 Objective
4.3 Hypotheses
4.4 Sampling Design
4.5 Statistical Treatment of Data
4.6 Use of Data
4.7 Sampling Procedure and Equipment
4.8 QA/QC
4.9 Data Quality Objectives
5.1 Introduction
5.2 Objective
5.3 Hypothesis
5.4 Sampling Design
5.5 Statistical Treatment of Data
5.6 Use of Data
5.7 Data Collection Parameters
5.8 Sampling Procedure and Equipment
5.9 QA/QC
6.1 Introduction
6.2 Objective
6.3 Hypothesis
6.4 Sampling Design
6.5 Statistical Treatment of Data
6.6 Use of Data
6.7 Data Collection Parameters
6.8 Sampling Procedure and Equipment
7 Human Health and Ecological Risk
Assessment
7.1 Introduction
7.2 Objective
7.3 Hypothesis
7.4 Sampling Design
7.5 Use of Data
8.1 Introduction
8.2 Objective
8.3 Hypothesis
8.4 Sampling Design
8.5 Statistical Treatment of Data
8.6 Use of Data
8.7 Use of Data
8.8 Benthic Micro-Infauna and Taxonomic Identification
9.1 Introduction
9.2 Sampling Design
10 Reporting
10.1 General
10.2 Reports
Annex A |
|
Annex B |
|
Annex C |
Since
early 1990s, contaminated sediment ([1])
arising from various
construction works in
The
environmental acceptability of the construction and operation of the Project
had been confirmed by findings of the associated Environmental Impact
Assessment (EIA) study completed in 2005 under Agreement No. CE 12/2002(EP) ([3]). The Director of Environmental Protection
(DEP) approved this EIA report under the Environmental
Impact Assessment Ordinance (Cap. 499) (EIAO) in September 2005 (EIA
Register No.: AEIAR-089/2005).
In
accordance with the EIA recommendation, prior to commencement of construction
works, the Civil Engineering and Development Department (CEDD) undertook a
detailed review and update of the EIA findings for the SB site ([4])
approved, in principle,
under Agreement No. CE
12/2002(EP) and the EIAO to assess for the EIA¡¦s relevance. Findings of the EIA review undertaken in
2009/ 2010 confirmed that the construction and operation of the SB site had
been predicted to be environmentally acceptable.
An
Environmental Permit (EP-427/2011) was issued by the Environmental Protection
Department (EPD) to the CEDD, the Permit Holder, on 3 November 2011 and varied
on 23 December 2011 (EP-427/2011/A).
Under
the requirements of Condition 4 of the EP (EP-427/2011/A), an EM&A
programme as set out in the Manual is required to be implemented.
This
Environmental Monitoring and Audit (EM&A) Manual (¡§the Manual¡¨) has been
prepared by ERM-Hong Kong, Limited (ERM) on behalf of CEDD.
The
purpose of the Manual is to provide information, guidance and instruction to
personnel charged with environmental duties and those responsible for
undertaking EM&A work during the construction and operation of the
Project. It provides systematic
procedures for monitoring and auditing of potential environmental impacts that
may arise from the works.
In
preparing this EM&A Manual for the SB Facility, reference has been made to
the Technical Memorandum of the
Environmental Impact Assessment Process (EIAO TM), the approved EIA Report (EIAO Register Number: AEIAR-089/2005) and
EM&A Manual for this Project ([5]), the EIA Review Report prepared under
the CEDD study Contaminated Sediment
Disposal Facility at South of Brothers (Agreement No. FM 2/2009), and the
EM&A Manual for the existing contaminated sediment disposal facility at ESC
(submitted under the Environment Permit
No. EP-312/2008/A).
The
EM&A Manual is an evolving document that should be updated to maintain its
relevance as the Project progresses.
The primary focus for review of the EM&A Manual will be to ensure
the impacts predicted and the recommended mitigation measures remain consistent
and appropriate to the manner in which the works are to be carried out.
This
second review of the EM&A Manual has been made to update the EM&A
requirements of the SB Facility in order to facilitate the subsequent
implementation of the respective EM&A works. Further reviews and subsequent updates
will be undertaken whenever necessary to take into account the findings
obtained during the Assignment as the works progress and will be presented in
separate documents.
The
proposed SB Facility is classified as a Designated Project by virtue of the
following items of Item C (Reclamation, Hydraulic and Marine Facilities,
Dredging and Dumping), Part I of Schedule 2 under EIAO:
¡P Item C.10 ¡V A Marine Dumping Area; and
¡P Item C.12 ¡V A dredging operation
exceeding 500,000 m3.
The
Project involves the sequential dredging, disposal of contaminated mud into,
and subsequent capping of the two dredged pits. Figure 1.1 presents the
location of the proposed site at SB.
The key components of the facility include the following:
¡P Dredging of two seabed pits (CMP 1 and
CMP 2) sequentially within the
proposed SB Facility Boundary;
¡P Backfilling each dredged pit sequentially with contaminated mud that
has been classified as requiring Type 2 disposal in accordance with ETWB TC(W) No. 34/2002; and
¡P Capping each backfilled pit sequentially with uncontaminated
material effectively isolating the contaminated mud from the surrounding marine
environment.
These
components constitute the construction and operation phases of the SB CAD
facility. They are the subject of
the EM&A programme.
Works
programme indicated that the SB Facility was put into service in phases in 2012
(Figure 1.2). The first pit (CMP 1) commenced dredging
in November 2012 and started to receive contaminated mud in September
2013. The second pit (CMP 2) at the
SB facility started backfilling in late November 2014. Capping will commence in December 2014
and is expected to be completed in 2016 for both pits. It should be noted that should the rate
at which contaminated mud arises change (either increasing or decreasing) then
SB CMPs may be capped earlier or later than 2016.
The
tentative project programme is presented in Figure 1.2.
It should be noted that the timeline presents predicted timeframes for
each works component.
Figure 1.2 Indicative
Works Programme at the South of The
Brothers Facility
The
broad objective of this EM&A Manual is to define the procedures of the
EM&A programme for monitoring the environmental performance of the Project
during construction and operation.
The construction and operational impacts resulting from the
implementation of the SB Facility are specified in the EIA Report and the
subsequent EIA Review Report. These
Reports also specify mitigation measures that need to be implemented to confirm
compliance with the required environmental criteria. These mitigation measures and their
implementation requirements are presented in the Implementation Schedule (Annex A).
The
EIA recommends that environmental monitoring will be necessary to assess the
effectiveness of measures implemented to mitigate potential water quality,
marine ecology and fisheries impacts during the construction and operation of
the proposed facility. Regular
environmental auditing is also recommended to confirm that potential impacts
from other sources are adequately addressed through the implementation of the
mitigation measures defined in the EIA/ EIA Review Reports.
The
objectives of the EM&A programme are as follows:
1)
To
monitor and report on the environmental impacts of the dredging operations
associated with the construction of the disposal pits;
2)
To
monitor and report on the environmental impacts due to capping operations of
the exhausted pits;
3)
To
monitor and report on the environmental impacts of the disposal of contaminated
marine sediments in the active pits and specifically to determine:
a.
changes/trends
caused by disposal activities in the concentrations of contaminants in
sediments adjacent to the pits;
b.
changes/trends
caused by disposal activities in the toxicity of sediment adjacent to the pits;
c.
changes/trends
caused by disposal activities in the concentrations of contaminants in tissues
of demersal marine life adjacent to and remote from the pits;
d.
impacts
on water quality and benthic ecology caused by the disposal activities; and
e.
the risks to human health and dolphin of
eating seafood taken in the marine area around the active pits.
4)
To
monitor and report on the environmental impacts of the disposal operation and
specifically to determine whether the methods of disposal are effective in
reducing the risks of adverse environmental impacts.
5)
To
monitor and report on the benthic recolonisation of the
capped pits and specifically to determine the difference in infauna
between the capped pits and adjacent sites.
6)
To
assess the impact of a major storm (Typhoon Signal No. 8 or above) on the
containment of any uncapped or partially capped pits.
7)
To
design and continually review the operation and monitoring programme and:
a.
to
make recommendations for changes to the operation that will rectify any
unacceptable environmental impacts; and
b.
to make recommendations for changes to
the monitoring programme that will improve the ability to cost effectively
detect environmental changes caused by the disposal activities.
8)
To
establish numerical decision criteria for defining impacts for each monitoring
component.
9)
To
provide supervision on the field works and laboratory works to be carried out
by contractors/laboratories.
The
specific objectives of each component are discussed in the relevant sections of
this EM&A Manual.
The
scope of this EM&A programme is to:
¡P Establish baseline water quality levels
at specified locations prior to dredging operations for the construction of the
SB Facility;
¡P Implement monitoring and inspection
requirements for water quality monitoring programme during dredging,
backfilling and capping of the SB Facility;
¡P Implement monitoring and inspection
requirements for sediment quality monitoring programme during backfilling
operations at the SB Facility;
¡P Implement monitoring and inspection
requirements for sediment toxicity monitoring programme during backfilling
operations at the SB Facility;
¡P Implement monitoring and inspection
requirements for the body burden (marine biota) monitoring programme during
backfilling operations at the SB Facility;
¡P Liaise with, and provide environmental
advice (as requested or when otherwise necessary) to site staff on the
comprehension and consequences of the environmental monitoring data;
¡P Identify and resolve environmental
issues and other functions as they may arise from the works;
¡P Check and quantify the Contractor's
overall environmental performance, implementation of Event and Action Plans
(EAPs), and remedial actions taken to mitigate adverse environmental effects as
they may arise from the works;
¡P Conduct monthly reviews of monitored
impact data as the basis for assessing compliance with the defined criteria and
to ensure that necessary mitigation measures are identified and implemented,
and to undertake additional ad hoc
monitoring and auditing as required by special circumstances;
¡P Evaluate and interpret all
environmental monitoring data to provide an early indication should any of the
environmental control measures or practices fail to achieve the acceptable
standards, and to verify the environmental impacts predicted in the EIA;
¡P Manage and liaise with other
individuals or parties concerning other environmental issues deemed to be
relevant to the construction and operation process; and
¡P Conduct regular site inspections of a
formal or informal nature to assess:
-
the
level of the Contractor¡¦s general environmental awareness;
-
the
Contractor¡¦s implementation of the recommendations in the EIA;
-
the
Contractor¡¦s performance as measured by the EM&A;
-
the
need for specific mitigation measures to be implemented or the continued usage
of those previously agreed;
-
to
advise the site staff of any identified potential environmental issues; and
-
submit regular EM&A reports which
summarise project monitoring and auditing data, with full interpretation
illustrating the acceptability or otherwise of any environmental impacts and
identification or assessment of the implementation status of agreed mitigation
measures.
To
ensure effective implementation and reporting on compliance with the stated
mitigation measures, as well as the monitoring and auditing requirements and
remedial actions defined in the EIA, an appropriate contractual and supervisory
framework needs to be established.
The basis of the framework within which implementation should be managed
overall is through the preparation of EMPs by the Contractor(s).
An
EMP is similar in nature to a quality plan and provides details of the means by
which the Contractor (and all subcontractors working to the Contractor) will
implement the recommended mitigation measures and achieve the environmental
performance standards defined in
The
EMP also provides opportunities for the Contractor to draw upon the strength of
other institutional processes such as ISO 9000/14000 to ensure that the
achievement of the required standards and fulfilment of commitments are
documented.
The
contractual requirement for an EMP would generally comprise appropriate
extracts from (and references to) the EIA Report and EM&A Manual, and
include such typical elements as the relevant statutory environmental
standards, general environmental control clauses and specific environmental
management clauses, as well as an outline of the scope and content of the
EMP. In drafting the documentation,
due consideration should be given to the predictive nature of the EIA process
and the consequent need to manage and accommodate the actual impacts arising
from the construction process. In
particular, the Contractor must be placed under a clear obligation to identify
and control any implications arising from changes to the working methods
assumed in the EIA, or to the progress rates and other estimates made during
the preliminary design phase.
The
EM&A will require the involvement of CEDD, an Environmental Team (ET),
Independent Auditor(s) and the Contractor.
The
CEDD will appoint an Environmental Team (ET) to conduct the monitoring and
auditing works and to provide specialist advice on the undertaking and
implementation of environmental responsibilities.
The
ET will have previous relevant experience with managing similarly sized
EM&A programmes and the Environmental Team Leader (ET Leader) will be a
recognised environmental professional, preferably with a minimum of seven years
relevant experience in impact assessments and impact monitoring programmes,
particularly with reference to those to the marine environment and where
possible related to marine dredging / disposal activities.
To
maintain strict control of the EM&A process, the CEDD will also appoint
Independent Auditor(s) to verify and validate the environmental performance of
the Contractor and the ET.
The
roles and responsibilities of the various parties involved in the EM&A
process are further expanded in the following sections. The ET Leader will be responsible for,
and in charge of, the Environmental Team; and will be the person responsible
for executing the EM&A requirements.
Reporting
to the CEDD, the Contractor will:
¡P Work within the scope of the
construction contract and other tender conditions;
¡P Provide assistance to the ET in
conducting the required environmental monitoring;
¡P Participate in the site inspections
undertaken by the ET, as required, and undertake any corrective actions
instructed by CEDD;
¡P Provide information/advice to the ET
regarding works activities which may contribute, or be contributing to the
generation of adverse environmental conditions;
¡P Implement measures to reduce impact
where Action and Limit levels are exceeded; and
¡P Take responsibility and strictly
adhere to the guidelines of the EM&A programme and complementary protocols
developed by their project staff.
The
CEDD will:
¡P Monitor the Contractor's compliance
with contract specifications, including the effective implementation and
operation of environmental mitigation measures and other aspects of the
EM&A programme;
¡P Employ Independent Auditor(s) to audit
the results of the EM&A works carried out by the ET;
¡P Comply with the agreed Event and
Action Plan in the event of any exceedance; and
¡P Instruct the Contractor to follow the
agreed protocols or those in the Contract Specifications in the event of
exceedances or complaints.
The
duties of the Environmental Team (ET) and Environmental Team Leader (ET Leader)
are to:
¡P Monitor the various environmental
parameters as required by this or subsequent revisions to the EM&A Manual;
¡P Assess the EM&A data and review
the success of the EM&A programme determining the adequacy of the
mitigation measures implemented and the validity of the EIA predictions as well
as identify any adverse environmental impacts before they arise;
¡P Conduct regular site inspections and
to investigate and inspect the Contractor's equipment and work methodologies
with respect to pollution control and environmental mitigation, monitor
compliance with the environmental protection specifications in the Contract,
and to anticipate environmental issues that may require mitigation before the
problem arises;
¡P Audit the environmental monitoring
data and report the status of the general site environmental conditions and the
implementation of mitigation measures resulting from site inspections;
¡P Review Contractor¡¦s working programme
and methodology, and comment as necessary;
¡P Investigate and evaluate complaints,
and identify corrective measures;
¡P Advice to the Contractor on
environmental improvement, awareness, enhancement matters, etc,
on site;
¡P Report on the environmental monitoring
and audit results and the wider environmental issues and conditions to the
Contractor, CEDD and the EPD; and
¡P Adhere to the agreed protocols or
those in the Contract Specifications in the event of exceedances or complaints.
The
ET will be led and managed by the ET leader. The ET leader will have relevant
education, training, knowledge, experience and professional qualifications
subject to the approval of the Director of Environmental Protection. Suitably qualified staff will be
included in the ET, and ET should not be in any way an associated body of the
Contractor.
¡P Review and audit the implementation of
the EM&A programme and the overall level of environmental performance being
achieved;
¡P Validate and confirm the accuracy of
monitoring results, monitoring equipment, monitoring stations, monitoring
procedures and locations of sensitive receivers;
¡P Audit the EIA recommendations and
requirements against the status of implementation of environmental protection
measures on site;
¡P Adhere to the procedures for carrying
out complaint investigation;
¡P Review, when required, the
effectiveness of environmental mitigation measures and project environmental
performance including the proposed corrective measures;
¡P Report, when required, the findings of
audits and other environmental performance reviews to CEDD, ET, EPD and the
Contractor.
The
independent auditor(s) will have relevant education, training, knowledge,
experience and professional qualifications subject to the approval of the
Director of Environmental Protection.
Independent auditor(s) should not be in any way an associated body of
the Contractor or the ET.
The
remainder of the Manual is set out as follows:
¡P Section 2 sets out the EM&A
general requirements;
¡P Section 3 details the methodologies,
parameters to be tested and the requirements for the marine water quality
monitoring for the dredging, backfilling and capping operations at the SB
Facility;
¡P Section 4 details the methodologies,
parameters to be tested and the requirements for sediment quality monitoring
for the backfilling activities at the SB Facility;
¡P Section 5 details the methodologies,
parameters to be tested and the requirements for sediment toxicity quality
monitoring for the backfilling activities at the SB Facility;
¡P Section 6 details the methodologies,
parameters to be tested and the requirements for marine biota monitoring for
the backfilling activities at the SB Facility;
¡P Section 7 details the requirements for
Human Health and Dolphin Risk Assessment;
¡P Section 8 details the requirements for
benthic re-colonisation assessment;
¡P Section 9 details the methodologies,
parameters to be tested and the requirements for the assessment of impacts due
to major storms; and
¡P Section 10 details the EM&A
reporting requirements.
In
this section, the general requirements of the EM&A programme are
presented. The scope and content of
the programme is developed with reference to the findings and recommendations
of the approved EIA Report (EIA Register
No.: AEIAR-089/2005) and the EIA Review.
Potential
environmental impacts associated with the construction and operation of the
Project, as identified during the EIA process, will be addressed through
monitoring and controls specified in this EM&A Manual and in the
construction contracts.
During
dredging and capping operations at the SB Facility, water quality will be
subject to EM&A, with environmental monitoring being undertaken for water
quality as determined in the EIA (see Section
3 for details).
During
backfilling operations at the SB Facility, water and sediment quality, marine
ecology and fisheries will be subject to EM&A, with environmental
monitoring being undertaken for these aspects (see Sections 3 to 9 for details).
The
environmental monitoring work for this Project will be carried out in
accordance with this EM&A Manual and reported by the ET.
Action
and Limit (A/L) Levels are defined levels of impact recorded by the
environmental monitoring activities which represent levels at which a
prescribed response is required.
This processes by which these levels should be quantitatively defined
are presented in the relevant sections of this Manual and described in
principle below:
¡P Action
Levels: beyond which
there is a clear indication of a deteriorating ambient environment for which
appropriate remedial actions are likely to be necessary to prevent
environmental quality from falling outside the Limit Levels, which would be unacceptable; and
¡P Limit
Levels: statutory
and/or agreed contract limits stipulated in the relevant pollution control
ordinances, HKPSG or Environmental Quality Objectives
established by the EPD. If these are
exceeded, works may not proceed without appropriate remedial action, including
a critical review of plant and working methods.
The
purpose of Event and Action Plans (EAPs) are to provide, in association with
the monitoring and audit activities, procedures for ensuring that if any
significant environmental incident (either accidental or through inadequate
implementation of mitigation measures on the part of the Contractor) does
occur, the cause will be quickly identified and remediated, and the risk of a
similar event recurring is reduced.
This also applies to the exceedances of A/L criteria to be identified in
the EM&A programme.
Enquiries,
complaints and requests for information can be expected from a wide range of
individuals and organisations including members of the public, Government
departments, the press and television media and community groups.
Enquiries,
complaints and requests for information concerning the environmental effects of
the Project, irrespective of how they are received, will be reported to CEDD
and directed to the ET Leader who will set up procedures for handling,
investigation and storage of such information. The following steps will then be
followed:
1)
The
ET Leader will notify CEDD of the nature of the enquiry.
2)
An
investigation will be initiated to determine the validity of the complaint and
to identify the source of the problem.
3)
The
ET Leader will undertake the following steps, as necessary:
a.
investigate
and identify source of the problem;
b.
if
considered necessary by CEDD undertake additional monitoring to verify the
existence and severity of the alleged complaint;
c.
liaise
with EPD to identify remedial measures;
d.
liaise
with CEDD and the Contractor to identify remedial measures;
e.
implement
the agreed mitigation measures;
f.
repeat
the monitoring to verify effectiveness of mitigation measures; and
g.
repeat review procedures to identify further
possible areas of improvement if the repeat monitoring results continue to substantiate
the complaint.
4)
The
outcome of the investigation and the action taken will be documented on a
complaint proforma (Annex B). A formal response to each complaint
received will be prepared by the ET Leader within a maximum of five working
days and submitted to CEDD, in order to notify the concerned person(s) that
action has been taken.
5)
All
enquiries which trigger this process will be reported in the EM&A reports
which will include results of inspections undertaken by the ET Leader, and
details of the measures taken, and additional monitoring results (if deemed
necessary). It should be noted that
the receipt of complaint or enquiry will not be, in itself, a sufficient reason
to introduce additional mitigation measures.
In
all cases the complainant will be notified of the findings, and audit
procedures will be put in place to ensure that the problem does not recur.
Monthly,
Quarterly and Annual reports will be prepared by the ET and submitted to CEDD,
EPD and AFCD. The reports will be
prepared and submitted within a specified period. Additional details on reporting
protocols are presented in Section 10.
The
cessation of EM&A programme is subject to the satisfactory completion of
the EM&A Final Review Report, with approval from
EPD.
This
Section provides details of the water quality monitoring to be undertaken
during the construction and operation of the SB Facility. Water quality modelling carried out for
this Project indicates that the potential water quality impacts associated with
the dredging, backfilling and capping works will be within acceptable levels
and no unacceptable water quality impacts are expected. However, the monitoring programme is
designed to verify the predictions of the EIA and confirm compliance with the
Water Quality Objectives (WQOs).
Water
quality monitoring for the Project can be divided into the following stages:
¡P Dredging activities to form the pits;
¡P Backfilling activities at active pits;
and
¡P Capping activities at backfilled
pits.
Each of these
is discussed in turn below.
Water
quality monitoring will be conducted during dredging of the two seabed pits at
South of The Brothers. Monitoring
will consist of the collection of baseline water quality data for the purposes
of the development of Action and Limit Levels, as well as impact monitoring
during dredging activities.
Baseline
monitoring will be conducted in the vicinity of the SB Facility and in
reference areas (EPD Water Quality Monitoring Stations NM 1, 2, 3, 5 and 6)
prior to the commencement of marine dredging works in order to gather
representative water quality data for the EM&A. Locations of the baseline monitoring
stations are shown in Figure 3.1 and the
coordinates are shown in Table 3.1.
The
baseline water quality monitoring will be undertaken three days per week at all
stations for four consecutive weeks prior to construction works. A sampling survey will include the
collection of all water samples and measurement of all in situ parameters during both mid-flood and mid-ebb tides at all
stations on the same day.
Monitoring works will be completed within a 4-hour window of 2 hours
before or after mid-flood and mid-ebb tides. The interval between two sampling surveys
will not be less than 36 hours.
Table 3.1 Coordinates
for Water Quality Monitoring Stations for Baseline Water Quality Monitoring for
Dredging Activities
Monitoring Stations |
Easting |
Northing |
Far
Field Stations |
|
|
SB-WFA |
805787 |
827951 |
SB-WFB |
806066 |
816537 |
Mid
Field Stations |
|
|
SB-WMA |
813001 |
821559 |
SB-WMB |
818386 |
822120 |
Near
Field Stations |
|
|
SB-WNAA |
814847 |
820043 |
SB-WNAB |
816197 |
819911 |
SB-WNBA |
813999 |
819207 |
SB-WNBB |
815505 |
819019 |
Reference
Stations |
|
|
NM1 |
820256 |
823214 |
NM2 |
816015 |
823686 |
NM3 |
812527 |
824049 |
NM5 |
807707 |
827244 |
NM6 |
807584 |
820286 |
Sensitive
Receiver Stations |
|
|
MW1 |
823604 |
823654 |
THB1 |
814514 |
817932 |
THB2 |
815873 |
818035 |
WSR45C |
817431 |
820211 |
WSR46 |
813880 |
820973 |
Note:
Coordinates are based on
Each
station will be sampled and measurements will be taken at three depths, 1 m below
the sea surface, mid depth and 1 m above the seabed. Where the water depth is less than 6 m
the mid-depth station may be omitted.
If the water depth is less than 3 m, only the mid-depth station will be
monitored.
For
in situ measurements, triplicate
readings shall be made at each water depth at each station. Triplicate water samples shall be
collected at each water depth at each station for laboratory measurements.
The
following suite of parameters should be measured as part of the baseline
monitoring:
¡P Dissolved Oxygen (mg L-1) (in situ);
¡P Salinity (ppt)
(in situ);
¡P pH (in situ);
¡P Turbidity (NTU) (in situ);
¡P Temperature (¢XC) (in situ);
¡P Current Velocity and Direction (ms-1)
(in situ);
¡P Suspended Solids (mg L-1)
(laboratory analysis);
¡P Ammonia (mg L-1)
(laboratory analysis);
¡P Total Inorganic Nitrogen (TIN mg L-1)
(laboratory analysis);
¡P 5-Day Biochemical Oxygen Demand (BOD5)
(mg L-1) (laboratory analysis);
¡P Cadmium (mg L-1)
(laboratory analysis);
¡P Chromium (mg L-1) (laboratory
analysis);
¡P Copper (mg L-1) (laboratory
analysis);
¡P Lead (mg L-1) (laboratory
analysis);
¡P Mercury (mg L-1)
(laboratory analysis);
¡P Nickel (mg L-1) (laboratory
analysis);
¡P Silver (mg L-1) (laboratory
analysis);
¡P Zinc (mg L-1) (laboratory
analysis); and,
¡P Arsenic (mg L-1)
(laboratory analysis).
In
addition to the water quality parameters, other relevant data will also be
measured and recorded in Water Quality Monitoring Logs, including the location
of the sampling stations, water depth, time, weather conditions, sea
conditions, tidal stage, special phenomena and work activities undertaken
around the monitoring and works area that may influence the monitoring
results.
Four
hard copies and one electronic copy of the Baseline
Monitoring Report will be submitted to the EPD at least two weeks before
commencement of construction of the Project.
Impact
monitoring for the dredging activities at SB will be conducted at mobile
stations around the dredging area.
Initially, the impact monitoring will be conducted at both mid-flood and
mid-ebb tides for three days per week.
The interval between two sets of monitoring shall normally not be less
than 36 hours. The frequency of
monitoring should be reviewed based on sufficient monitoring results (e.g. from
the first three months of monitoring) to determine whether reductions can be
made. Subsequent revision(s) of
monitoring frequency shall be confirmed upon agreement with the EPD.
The
location of the mobile monitoring stations is dependent on the location of the
dredging activities. These mobile
stations will be located at an appropriate distance between each other along
the up-current and down-current transect for the dredging area. The following methodology will be adopted
to determine the precise location of the mobile stations on each sampling
occasion:
¡P Contact the CEDD barge one day before
the survey day for every sampling occasion to determine the dredging schedule
for that particular survey day and to determine the likely location of dredging
at the proposed time of sampling;
¡P Determine current direction at
mid-depth at one station upstream and one station downstream of the SB Facility
during both mid-flood and mid-ebb tide;
¡P Determine a suitable location for the
station transect (the first down-current station will be located on the down
current edge, and first up-current station will be located on the up-current
edge, according to the current direction and the position of dredging at the
time of sampling); and
¡P Collect samples from the stations
located on a transect running up-current and
down-current of the dredging area.
There
will be two stations located up-current and five stations down-current of the
monitoring transect. A 500 m
separation distance will be adopted between adjacent stations except between
adjacent upstream and downstream stations which are located on the pit
edge. In addition, water samples
will be collected from the Sensitive Receiver stations at Sham Shui Kok, Tai Mo To, Ma Wan and
Tai Ho Bay as shown in Figures 3.2a and 3.2b.
Locations of upstream and downstream stations are illustrated in Figures 3.2a and 3.2b based on assumed
current direction and dredging position during monitoring.
Each
station will be sampled and measurements will be taken at three depths, 1 m
below the sea surface, mid depth and 1 m above the seabed. Triplicate water samples and
measurements will be taken at each depth.
Where water depth is less than 6m the mid-depth station may be
omitted. If water depth is less
than 3m, only the mid-depth station will be monitored.
The
following suite of parameters should be measured as part of the impact
monitoring for dredging:
¡P Dissolved Oxygen (mg L-1) (in situ);
¡P Salinity (ppt)
(in situ);
¡P pH (in situ);
¡P Turbidity (NTU) (in situ);
¡P Temperature (¢XC) (in situ)
¡P Current Velocity and Direction (ms-1)
(in situ); and,
¡P Suspended Solids (mg L-1)
(laboratory analysis).
In
addition to the water quality parameters, other relevant data will also be
measured and recorded in Water Quality Monitoring Logs, including the location
of the sampling stations, water depth, time, weather conditions, sea
conditions, tidal stage, special phenomena and work activities undertaken
around the monitoring and works area that may influence the monitoring results.
Impact
monitoring for dredging activities will be evaluated against Action and Limit
Levels. The key assessment
parameters are dissolved oxygen (DO) and suspended solids (SS) and thus Action
and Limit Levels based on the assessment criteria are identified for these
parameters. However, turbidity can
also provide valuable instantaneous information on water quality and thus an
Action Limit is measured for this parameter to facilitate quick responsive
action in the event of any apparent unacceptable deterioration attributable to
the works. Baseline data will be
taken into account in setting Action and Limit Levels, however, the rationale
are shown in Table 3.2.
Action
and Limit Levels are used to determine whether operational modifications are
necessary to mitigate impacts to water quality ([6]).
In the event that the levels are exceeded, appropriate actions in Event
and Action Plans (Table 3.3) should
be undertaken.
Table 3.2 Action
and Limit Levels of Water Quality for Dredging Activities
Parameter |
Action Level |
Limit Level |
Dissolved Oxygen |
|
|
Surface
and Middle Depth Averaged |
The
average of the impact, WSR 45C and WSR 46 station readings are < 5%ile of
baseline data = 4.32 mg L-1 and
Significantly
less than the reference stations mean DO (at the same tide of the same day) |
The
average of the impact, WSR 45C and WSR 46 station readings are and Significantly
less than the reference stations mean DO (at the same tide of the same day) |
Bottom |
The
average of the impact, WSR 45C and WSR 46 station readings are < 5%ile of
baseline data = 3.12 mg L-1 and Significantly
less than the reference stations mean DO (at the same tide of the same day) |
The
average of the impact, WSR 45C and WSR 46 station readings are and Significantly
less than the reference stations mean DO (at the same tide of the same day) |
Suspended Solids |
|
|
Depth
Averaged |
The
average of the impact, WSR 45C and WSR 46 station readings are > 95%ile of
baseline data = 21.60 mg L-1 and 120%
or more of the reference stations SS (at the same tide of the same day) |
The
average of the impact, WSR 45C and WSR 46 station readings are > 99%ile of
baseline data = 40.10 mg L-1 and 130%
or more of the reference stations SS (at the same tide of the same day) |
Turbidity |
|
|
Depth
Averaged |
The
average of the impact, WSR 45C and WSR 46 station readings are > 95%ile of
baseline data = 25.04 NTU and 120%
or more of the reference stations turbidity (at the same tide of the same
day) |
The
average of the impact, WSR 45C and WSR 46 station readings are > 99% of
baseline data = 32.68 NTU and 130%
or more of the reference stations turbidity (at the same tide of the same
day) |
Table 3.3 Water
Quality Event and Action Plan during Dredging Operations
Event |
Environmental Team |
Contractor |
Action level |
|
|
Exceedance
for one occasion |
¡P
Repeat
in-situ measurement to confirm
findings; ¡P
Identify
the source(s) of impact; ¡P
Inform
contractor and contractor informs CEDD, EPD and AFCD and confirm notification
of the non-compliance in writing; ¡P
Check
monitoring data; ¡P
Discuss
potential mitigation measures if exceedance is attributed to the works with
contractor. |
¡P
Discuss
potential mitigation measures with ET and agree on mitigation measures to be
implemented if exceedance is attributed to the works; ¡P
Ensure
mitigation measures are implemented; ¡P
Assess
the effectiveness of the implemented mitigation measures. |
Limit Level |
|
|
Exceedance
for one occasion |
¡P
Repeat
in-situ measurement to confirm findings; ¡P
Identify
source(s) of impact; ¡P
Inform
contractor and contractor informs CEDD, EPD and AFCD; ¡P
Discuss
further mitigation measures if exceedance is attributed to the works with
contractor; ¡P
Increase
the monitoring frequency to daily if exceedance is attributed to the works
until no exceedance of the Limit Level. |
¡P
Critical
review of working methods; ¡P
Check
plant, equipment and working methods; ¡P
Discuss
further mitigation measures with ET to be implemented if exceedance is
attributed to the works; ¡P
Ensure
mitigation measures are being implemented; ¡P
Assess
the effectiveness of the implemented mitigation measures |
Limit
Level exceeded on two or more occasions |
¡P
Identify
source(s) of impact; ¡P
Inform
contractor and contractor informs, CEDD, EPD and AFCD. |
¡P
If
exceedance is attributed to the works consider and if necessary reduce works
until no exceedance of Limit Level |
Impacts
attributable to works |
¡P
Inform
contractor and contractor informs, CEDD, EPD and AFCD. |
¡P
Comprehensive
review of works; ¡P
Reduce
works; and ¡P
Suspension
of works. |
The
main objective of this component is to determine the impacts, if any, of backfilling
activities at SB Facility on water quality. Two separate components of water quality
monitoring are necessary:
¡P Routine
Water Quality Monitoring
¡V conducted to examine the impacts of backfilling activities on the level of
inorganic metal contaminants in marine waters; and
¡P Water
Column Profiling ¡V
conducted to examine in situ the
impacts of backfilling operations on water quality parameters within the water
column.
The
impact hypothesis for this work component has been defined based on the
predictions from the EIA regarding impacts from the contaminated mud disposal
operations and the objectives for the EM&A.
Backfilling (disposal)
operations do not result in any exceedances of Northwestern
Water Quality Control Zone (NWWCZ) Water Quality Objectives (WQO).
As
a consequence of performing two separate tasks for assessing the impacts of
backfilling operations on water quality, two null hypotheses will be tested:
Routine Water Quality
Monitoring
H0 There are no differences in the levels
of contaminants in water samples in the plume arising from the backfilling
works and background levels in the vicinity of the backfilling.
Water
Column Profiling
H0 There is no change in the level of
compliance with the NWWCZ WQOs of samples taken from the plume arising from
backfilling activities (EIA predicted location).
Routine
water quality monitoring will be undertaken during backfilling activities at
mid-ebb or mid-flood tide. Water
samples will be collected at specific stations at fixed location, which should
be located in three areas at increasing distances from the active pit
(Reference, Intermediate and Impact stations/areas). Additional Sensitive Receiver stations
at Sham Shui Kok, Tai Mo
To, Ma Wan and Tai Ho Bay will be sampled.
The design for this component of the programme allows impacts, if any,
to water quality as a result of the backfilling activities in the vicinity of
SB Facility to be assessed.
The
number of monitoring stations sampled depends on the state of the tide. During the ebb tide, water samples are
collected from five up-current Reference Stations, five down-current Impact
Stations and five down-current Intermediate Stations. During the flood tide, water samples are
collected from three up-current Reference Stations, three down-current Impact
Stations and three down-current Intermediate Stations. The approach will ensure that the impact
of temporal changes on the hydrodynamic conditions in the area is considered in
the sampling.
The
following suite of parameters should be measured as part of routine water
quality monitoring operations:
¡P Dissolved Oxygen (mg L-1) (in situ);
¡P Salinity (ppt)
(in situ);
¡P pH (in situ);
¡P Turbidity (NTU) (in situ);
¡P Temperature (¢XC) (in situ)
¡P Current Velocity and Direction (ms-1)
(in situ);
¡P Suspended Solids (mg L-1)
(laboratory analysis);
¡P Ammonia (mg L-1)
(laboratory analysis);
¡P Total Inorganic Nitrogen (TIN mg L-1)
(laboratory analysis);
¡P 5-Day Biochemical Oxygen Demand (BOD5)
(mg L-1) (laboratory analysis)
¡P Cadmium (mg L-1)
(laboratory analysis);
¡P Chromium (mg L-1)
(laboratory analysis);
¡P Copper (mg L-1) (laboratory
analysis);
¡P Lead (mg L-1) (laboratory
analysis);
¡P Mercury (mg L-1)
(laboratory analysis);
¡P Nickel (mg L-1) (laboratory
analysis);
¡P Silver (mg L-1) (laboratory
analysis);
¡P Zinc (mg L-1) (laboratory
analysis); and
¡P Arsenic (mg L-1)
(laboratory analysis).
In
addition to the water quality parameters, other relevant data will also be
measured and recorded in Water Quality Monitoring Logs, including the location
of the sampling stations, water depth, time, weather conditions, sea
conditions, tidal stage, special phenomena and work activities undertaken
around the monitoring and works area that may influence the monitoring results.
The
locations of monitoring stations during ebb and flood tides are shown in Figures 3.3 and 3.4, respectively, and
the coordinates are shown Table 3.4. Additional monitoring stations at Sham Shui Kok, Tai Mo To, Ma Wan and
Tai Ho Bay will be sampled. Review
of first four months Routine Water
Quality Monitoring which were conducted three times per week in October
2013, November 2013, January 2014 and February 2014 indicated that there did not appear to
indicate any unacceptable deterioration in water quality in all of the sampling
events ([7]). Therefore, the sampling frequency and number of
replicates will remain the same as those currently proposed for the CMP V
EM&A programme and will be used for SB monitoring as a consistent and
conservative approach. Eight
replicate samples will be collected from each monitoring station, for eight
times per year, twice in the dry season, twice during the wet season and twice
in each of the two transitional seasons.
For
a given sampling event water samples and in
situ measurements should be taken at mid-depth of all stations during the
same tidal state (ie mid-ebb or mid-flood tide), with
the exception of Dissolved Oxygen, Suspended Solids and Turbidity for which the
sampling/measurements should be taken at both mid-depth and bottom level of all
stations during the same tidal state.
Sampling frequency and number of replicates for the SB Facility will be
reviewed and adjusted accordingly based on power analyses in each Annual Review Report.
Routine
water quality monitoring for SB will be undertaken during its backfilling
activities, which begin in September 2013.
Details on the Sampling Programme are shown in Annex C.
Table 3.4 Coordinates
of Monitoring Stations for Routine Water Quality Monitoring during Backfilling
Operations and Water Quality Monitoring during Capping Operations
Monitoring Stations |
Easting |
Northing |
Ebb Tide |
|
|
Reference Stations |
|
|
SB-RFE1 |
814191 |
822133 |
SB-RFE2 |
814532 |
822458 |
SB-RFE3 |
814915 |
822758 |
SB-RFE4 |
815356 |
823032 |
SB-RFE5 |
815880 |
823215 |
Impact Stations |
|
|
SB-IPE1 |
814949 |
818257 |
SB-IPE2 |
815257 |
818549 |
SB-IPE3 |
815526 |
818888 |
SB-IPE4 |
815790 |
819189 |
SB-IPE5 |
816064 |
819615 |
Intermediate Stations |
|
|
SB-INE1 |
812140 |
819107 |
SB-INE2 |
812460 |
818834 |
SB-INE3 |
812941 |
818337 |
SB-INE4 |
813230 |
818850 |
SB-INE5 |
812577 |
817788 |
Sensitive Receiver
Stations |
|
|
MW1 |
823603 |
823653 |
THB1 |
814514 |
817932 |
THB2 |
815873 |
818035 |
WSR45C |
817431 |
820211 |
WSR46 |
813880 |
820973 |
Flood Tide |
|
|
Reference Stations |
|
|
SB-RFF1 |
815058 |
818400 |
SB-RFF2 |
815623 |
818964 |
SB-RFF3 |
816147 |
819427 |
Impact Stations |
|
|
SB-IPF1 |
814430 |
819936 |
SB-IPF2 |
813887 |
819291 |
SB-IPF3 |
815128 |
820361 |
Intermediate Stations |
|
|
SB-INF1 |
812902 |
822410 |
SB-INF2 |
814111 |
822914 |
SB-INF3 |
815421 |
823317 |
Sensitive Receiver
Stations |
|
|
MW1 |
823603 |
823653 |
THB1 |
814514 |
817932 |
THB2 |
815873 |
818035 |
WSR45C |
817431 |
820211 |
WSR46 |
813880 |
820973 |
Note:
Coordinates are based on
Water
column profiling will be undertaken during backfilling activities. There are two monitoring stations for
Water Column Profiling. The two
monitoring stations will be mobile, and their locations will be dependent on
the position of the disposal barge at the time of monitoring. The two mobile monitoring stations will
be approximately 100 m upstream and downstream of the disposal area,
respectively.
The
following suite of parameters should be measured as part of the water column
profiling:
¡P Salinity (ppt)
(in situ);
¡P Dissolved Oxygen (mg L-1) (in situ);
¡P Turbidity (NTU) (in situ);
¡P Temperature (¢XC) (in situ)
¡P Current Velocity and Direction (m s-1)
(in situ)
¡P pH (in situ); and
¡P Suspended Solids (mg L-1)
(laboratory analysis).
In
addition to the water quality parameters, other relevant data will also be
measured and recorded in Water Quality Monitoring Logs, including the location
of the sampling stations, water depth, time, weather conditions, sea conditions,
tidal stage, special phenomena and work activities undertaken around the
monitoring and works area that may influence the monitoring results.
Water
Column Profiling will be conducted monthly. Four replicate samples for SS will be
collected at mid-depth from each of the monitoring stations during each
sampling event. The sampling
frequency and number of replicates are the same as those currently proposed for
the CMP V EM&A programme and will initially be used for SB monitoring as a
consistent and conservative approach.
During each sampling event in situ
measurements should be taken at 1 m depth intervals through the water column
for a period of one hour at each station.
All water samples and in situ
measurements should be taken during the same tidal state (ie
mid-ebb or mid-flood tide) of a given sampling event. Sampling frequency and the number of
replicates for SB will be reviewed and adjusted accordingly based on power
analyses in each Annual Review Report. Details on the Sampling Programme for the SB Facility are shown in Annex C.
Routine
water quality monitoring for backfilling activities will be evaluated against
Action and Limit Levels. The key
assessment parameters are dissolved oxygen (DO) and suspended solids (SS) and
thus Action and Limit Levels based on the assessment criteria are identified
for these parameters. However,
turbidity can also provide valuable instantaneous information on water quality
and thus an Action Limit is measured for this parameter to facilitate quick
responsive action in the event of any apparent unacceptable deterioration
attributable to the works. Baseline
data will be taken into account in setting Action and Limit levels, however,
the rationale are shown in Table 3.5.
Action
and limit levels are used to determine whether operational modifications are
necessary to mitigate impacts to water quality ([8]) ([9]).
In the event that the levels are exceeded, appropriate actions in Event
and Action Plans (Table 3.6) should
be undertaken.
Table 3.5 Action
and Limit Levels of Water Quality for Backfilling Activities
Parameter |
Action Level |
Limit Level |
Dissolved Oxygen |
|
|
Surface
and Middle Depth Averaged |
The
average of the impact, WSR 45C and WSR 46 station readings are < 5%ile of
baseline data and
Significantly
less than the reference stations mean DO (at the same tide of the same day) |
The
average of the impact, WSR 45C and WSR 46 station readings are < 4 mg/L and Significantly
less than the reference stations mean DO (at the same tide of the same day) |
Bottom |
The
average of the impact, WSR 45C and WSR 46 station readings are < 5%ile of
baseline data and Significantly
less than the reference stations mean DO (at the same tide of the same day) |
The
average of the impact, WSR 45C and WSR 46 station readings are < 2 mg/L and Significantly
less than the reference stations mean DO (at the same tide of the same day) |
Suspended Solids |
|
|
Depth
Averaged |
The
average of the impact, WSR 45C and WSR 46 station readings are > 95%ile of
baseline data and 120%
or more of the reference stations SS (at the same tide of the same day) |
The
average of the impact, WSR 45C and WSR 46 station readings are > 99%ile of
baseline data and 130%
or more of the reference stations SS (at the same tide of the same day) |
Turbidity |
|
|
Depth
Averaged |
The
average of the impact, WSR 45C and WSR 46 station readings are > 95%ile of
baseline data and 120%
or more of the reference stations turbidity (at the same tide of the same
day) |
The
average of the impact, WSR 45C and WSR 46 station readings are > 99% of
baseline data and 130%
or more of the reference stations turbidity (at the same tide of the same
day) |
Table 3.6 Water
Quality Event and Action Plan during Backfilling Operations
Event |
Environmental Team |
Contractor |
Action level |
|
|
Exceedance
for one occasion |
¡P
Repeat
in-situ measurement to confirm
findings; ¡P
Identify
the source(s) of impact; ¡P
Inform
contractor and contractor informs CEDD, EPD and AFCD and confirm notification
of the non-compliance in writing; ¡P
Check
monitoring data; ¡P
Discuss
potential mitigation measures if exceedance is attributed to the works with
contractor. |
¡P
Discuss
potential mitigation measures with ET and agree on mitigation measures to be
implemented if exceedance is attributed to the works; ¡P
Ensure
mitigation measures are implemented; ¡P
Assess
the effectiveness of the implemented mitigation measures. |
Limit Level |
|
|
Exceedance
for one occasion |
¡P
Repeat
in-situ measurement to confirm findings; ¡P
Identify
source(s) of impact; ¡P
Inform
contractor and contractor informs CEDD, EPD and AFCD; ¡P
Discuss
further mitigation measures if exceedance is attributed to the works with
contractor; ¡P
Increase
the monitoring frequency to daily if exceedance is attributed to the works
until no exceedance of the Limit Level. |
¡P
Critical
review of working methods; ¡P
Check
plant, equipment and working methods; ¡P
Discuss
further mitigation measures with ET to be implemented if exceedance is
attributed to the works; ¡P
Ensure
mitigation measures are being implemented; ¡P
Assess
the effectiveness of the implemented mitigation measures |
Limit
Level exceeded on two or more occasions |
¡P
Identify
source(s) of impact; ¡P
Inform
contractor and contractor informs, CEDD, EPD and AFCD. |
¡P
If
exceedance is attributed to the works consider and if necessary reduce works
until no exceedance of Limit Level |
Impacts
attributable to works |
¡P
Inform
contractor and contractor informs, CEDD, EPD and AFCD. |
¡P
Comprehensive
review of works; ¡P
Reduce
works; and ¡P
Suspension
of works. |
The
hierarchy of sampling design should allow for the application of nested
analysis of variance to statistically test any changes or trends in the
dataset. Under the nested design,
differences will be tested between stations in a particular area and between
the three areas (ie Impact, Intermediate and
Reference). Once a time series of
data has been gathered temporal changes in water quality parameters can be
analysed for significant differences.
In addition, the data gathered will be examined against the water
quality objectives for the NWWCZ to determine if the relevant water quality
objectives have been exceeded.
Monitoring
results for metals will be compared with the EIA predictions to verify that
potential impacts to water quality or contaminant dispersion in the plumes
arising from backfilling activities are no worse than as predicted.
The
data gathered will be examined graphically against the water quality objectives
for the NWWCZ to determine if the relevant water quality objectives have been
exceeded for any apparent impacts arising from the backfilling activities.
Should
increases be detected in the level of contaminants or exceedances of the NWWCZ
WQOs be detected, a review of the other monitoring parameters will be
undertaken. This will focus on
sampling stations in the vicinity of the water quality stations where increases
are detected to see if these can be attributed to contaminant spread from the
active pits. If so, consideration
will be given to revise the facility operations plan and backfilling activities
to reduce the spread of contaminants in the plume and achieve compliance with
WQOs.
The
design for this component of the programme allows impacts to water quality as a
result of the overall capping activities of the SB Facility to be
assessed. Replicate water samples
will be collected at specific stations, which should be located in three
discrete areas: Impact, Intermediate and Reference. The number of monitoring stations
sampled depends on the state of the tide.
During the ebb tide, water samples will be collected from five
up-current Reference Stations, five down-current Impact Stations and five
down-current Intermediate Stations.
During the flood tide, water samples will be collected at three up-current
Reference Stations, three down-current Impact Stations and three down-current
Intermediate Stations.
The
following suite of parameters should be measured as part of the impact
monitoring for capping operations:
¡P Dissolved Oxygen (mg L-1) (in situ);
¡P Salinity (ppt)
(in situ);
¡P pH (in situ);
¡P Turbidity (NTU) (in situ);
¡P Temperature (¢XC) (in situ)
¡P Current Velocity and Direction (ms-1)
(in situ);
¡P Suspended Solids (mg L-1)
(laboratory analysis);
¡P Ammonia (mg L-1)
(laboratory analysis);
¡P Total Inorganic Nitrogen (TIN mg L-1)
(laboratory analysis); and
¡P 5-Day Biochemical Oxygen Demand (BOD5)
(mg L-1) (laboratory analysis).
In
addition to the water quality parameters, other relevant data will also be
measured and recorded in Water Quality Monitoring Logs, including the location
of the sampling stations, water depth, time, weather conditions, sea
conditions, tidal stage, special phenomena and work activities undertaken
around the monitoring and works area that may influence the monitoring
results.
The
locations of stations during ebb and flood tides for SB are the same as those
proposed for Routine Water Quality Monitoring during backfilling activities (Figures 3.3 and 3.4; Table 3.4). Additional Sensitive Receiver stations
at Sham Shui Kok, Tai Mo
To, Ma Wan and Tai Ho Bay will be sampled for both ebb and flood tides. Given that the maximum disposal rate of
clean mud to be capped at SB is the same as that of contaminated mud for
backfilling at SB as stated in the EP, it is recommended that the sampling
frequency should remain the same as proposed for the CMP V EM&A programme
following the review of the first four months Routine Water Quality Monitoring results, which indicated that
there did not appear to indicate any unacceptable deterioration in water quality.
Therefore, samples will be collected four times per year, twice in the
dry season and twice during the wet season. Three replicate water samples will be
collected from mid-depth at each monitoring station during each sampling event,
with the exception of Suspended Solids for which the sampling should be taken
at both mid-depth and bottom level at each monitoring station during each
sampling event. In addition, in situ measurements should be taken at
mid-depth and bottom level of all stations during the same tidal state (ie mid-ebb or mid-flood tide) during a sampling event. All water samples and in situ measurements should be taken
during the same tidal state (ie mid-ebb or mid-flood
tide) of a given sampling event.
Sampling will be undertaken during capping activities for SB as detailed
in the Sampling Programme shown in Annex C.
The
sampling frequency and number of replicates are the same as those currently
proposed for the CMP V EM&A programme and will be used for SB monitoring as
a consistent and conservative approach.
These will be reviewed and adjusted accordingly based on power analyses
in each Annual Review Report.
Routine
water quality monitoring for capping activities will be evaluated against
Action and Limit Levels. The key
assessment parameters are dissolved oxygen (DO) and suspended solids (SS) and
thus Action and Limit Levels based on the assessment criteria are identified
for these parameters. However,
turbidity can also provide valuable instantaneous information on water quality
and thus Action and Limit Levels are measured for this parameter to facilitate
quick responsive action in the event of any apparent unacceptable deterioration
attributable to the works. Baseline
data will be taken into account in setting Action and Limit levels, however,
the rationale are shown in Table 3.7.
Action
and Limit Levels are used to determine whether operational modifications are
necessary to mitigate impacts to water quality ([10]).
In the event that the levels are exceeded, appropriate actions in Event
and Action Plans (Table 3.8) should
be undertaken.
Table 3.7 Action
and Limit Levels of Water Quality for Capping Activities
Parameter |
Action Level |
Limit Level |
Dissolved Oxygen |
|
|
Surface
and Middle Depth Averaged |
The
average of the impact, WSR 45C and WSR 46 station readings are < 5%ile of
baseline data = 4.32 mg L-1 and
Significantly
less than the reference stations mean DO (at the same tide of the same day) |
The
average of the impact, WSR 45C and WSR 46 station readings are and Significantly
less than the reference stations mean DO (at the same tide of the same day) |
Bottom |
The
average of the impact, WSR 45C and WSR 46 station readings are < 5%ile of
baseline data = 3.12 mg L-1 and Significantly
less than the reference stations mean DO (at the same tide of the same day) |
The
average of the impact, WSR 45C and WSR 46 station readings are and Significantly
less than the reference stations mean DO (at the same tide of the same day) |
Suspended Solids |
|
|
Depth
Averaged |
The
average of the impact, WSR 45C and WSR 46 station readings are > 95%ile of
baseline data = 21.60 mg L-1 and 120%
or more of the reference stations SS (at the same tide of the same day) |
The
average of the impact, WSR 45C and WSR 46 station readings are > 99%ile of
baseline data = 40.10 mg L-1 and 130%
or more of the reference stations SS (at the same tide of the same day) |
Turbidity |
|
|
Depth
Averaged |
The
average of the impact, WSR 45C and WSR 46 station readings are > 95%ile of
baseline data = 25.04 NTU and 120%
or more of the reference stations turbidity (at the same tide of the same
day) |
The
average of the impact, WSR 45C and WSR 46 station readings are > 99% of
baseline data = 32.68 NTU and 130%
or more of the reference stations turbidity (at the same tide of the same
day) |
Table 3.8 Water
Quality Event and Action Plan during Capping Operations
Event |
Environmental Team |
Contractor |
Action level |
|
|
Exceedance
for one occasion |
¡P
Repeat
in-situ measurement to confirm
findings; ¡P
Identify
the source(s) of impact; ¡P
Inform
contractor and contractor informs CEDD, EPD and AFCD and confirm notification
of the non-compliance in writing; ¡P
Check
monitoring data; ¡P
Discuss
potential mitigation measures if exceedance is attributed to the works with
contractor. |
¡P
Discuss
potential mitigation measures with ET and agree on mitigation measures to be
implemented if exceedance is attributed to the works; ¡P
Ensure
mitigation measures are implemented; ¡P
Assess
the effectiveness of the implemented mitigation measures. |
Limit Level |
|
|
Exceedance
for one occasion |
¡P
Repeat
in-situ measurement to confirm findings; ¡P
Identify
source(s) of impact; ¡P
Inform
contractor and contractor informs CEDD, EPD and AFCD; ¡P
Discuss
further mitigation measures if exceedance is attributed to the works with
contractor; ¡P
Increase
the monitoring frequency to daily if exceedance is attributed to the works
until no exceedance of the Limit Level. |
¡P
Critical
review of working methods; ¡P
Check
plant, equipment and working methods; ¡P
Discuss
further mitigation measures with ET to be implemented if exceedance is
attributed to the works; ¡P
Ensure
mitigation measures are being implemented; ¡P
Assess
the effectiveness of the implemented mitigation measures |
Limit
Level exceeded on two or more occasions |
¡P
Identify
source(s) of impact; ¡P
Inform
contractor and contractor informs, CEDD, EPD and AFCD. |
¡P
If
exceedance is attributed to the works consider and if necessary reduce works
until no exceedance of Limit Level |
Impacts
attributable to works |
¡P
Inform
contractor and contractor informs, CEDD, EPD and AFCD. |
¡P
Comprehensive
review of works; ¡P
Reduce
works; and ¡P
Suspension
of works. |
In situ water quality monitoring (salinity,
temperature, current velocity and direction) will be conducted using the
equipment listed in Section 3.6.1 and
following the testing protocols detailed in Section
3.6.2. In order to ensure the
reliability and quality of the data, the measuring instrument will be
calibrated prior to each sampling cruise and the probe of the measuring
instrument will be maintained at a suitable distance from the seabed to avoid
re-suspension of bottom sediments from skewing the results.
Water
quality profiling will be conducted continuously for a one-hour period from a
fixed point. After deployment, the
probe of the measuring equipment will be allowed to equilibrate with the
surrounding seawater for approximately 30 seconds. Subsequently, average readings will be
taken every few seconds to minimise sampling noise arising from the sensitivity
of the equipment.
In
addition to in situ water quality
monitoring, water samples will be collected in a water sampler. Samples will be stored in sealed
sampling bottles and chilled, and on completion of the survey will be
transported to the laboratory for immediate analysis. Samples not for immediate analysis will
be stored at 4 ¡Ó 2¢XC.
The
following equipment will be supplied and used by the contractor for the water
quality monitoring:
¡P Positioning
Device - Horizontal
positioning will be used and determined by a differential Global Positioning
System (dGPS) with the differential signal being
provided by a UHF differential transmitter. The UHF system should provide an
accuracy of better than 3m at the 95% confidence level to ensure the survey
vessel is in the correct location before taking measurements. The dGPS will
be calibrated daily before each survey period or results reported. And all data will be printed and logged
on disc.
¡P Electronic
data logging device -
A data logging device capable of storing measurement data will be used. The device will be able to read and
store the output from all electronic meters used for this project and will
record time and location as measured by the GPS.
¡P Dissolved
Oxygen and Temperature Measuring Equipment ¡V The instrument will be a portable, weatherproof
dissolved oxygen measuring instrument complete with cable, sensor,
comprehensive operation manuals, and will be operable from a DC power
source. It will be capable of
measuring: dissolved oxygen levels in the range of 0 - 20 mg L-1 and
0 - 200% saturation; and a temperature of 0 - 45 degrees Celsius. It will have a membrane electrode with
automatic temperature compensation complete with a cable of not less than 20 m
in length. Sufficient stocks of
spare electrodes and cables will be available for replacement where necessary
(for example, YSI model 59 metre, YSI 5739 probe, YSI 5795A submersible stirrer
with reel and cable or an approved similar instrument).
¡P Turbidity
Measurement Equipment
- Turbidity within the water will be measured in situ by the nephelometric method.
The instrument will be a portable, weatherproof turbidity-measuring unit
complete with cable, sensor and comprehensive operation manuals. The equipment will be operated from a DC
power source, it will have a photoelectric sensor capable of measuring
turbidity between 0 - 1000 NTU and will be complete with a cable with at least
20 m in length (Hach 2100P or an approved similar
instrument).
¡P Salinity
Measurement Instrument
- A portable salinometer capable of measuring
salinity in the range of 0 - 40 ppt will be provided
for measuring salinity of the water at each monitoring location.
¡P pH meter ¡V A portable pH meter capable of
measuring a range between 0.0 and 14.0 will be provided to measure pH in marine
waters.
¡P Suspended
Solid Measurement Equipment
- A water sampler (eg Kahlsic
Water Sampler), which is a PVC cylinder (capacity not less than 2 litres) which
can be effectively sealed with latex cups at both ends, will be used for
sampling. The sampler will have a
positive latching system to keep it open and prevent premature closure until released
by a messenger when the sampler is at the selected water depth. Water samples for suspended solids
measurement will be collected in high density polythene bottles, packed in ice
(cooled to 4oC without being frozen), and delivered to the laboratory
in the same day as the samples were collected.
¡P Water
Depth Gauge - A
portable, battery-operated echo sounder (Seafarer 700 or a similar approved
instrument) will be used for the determination of water depth at each
designated monitoring station. This
unit will either be hand-held or affixed to the bottom of the work boat if the
same vessel is to be used throughout the monitoring programme.
¡P Water
Sampling Equipment -
A water sampler, consisting of a transparent PVC or glass cylinder of not less
than two litres which can be effectively sealed with cups at both ends, will be
used (Kahlsico Water Sampler 13SWB203 or an approved
similar instrument). The water
sampler will have a positive latching system to keep it open and prevent
premature closure until released by a messenger when the sampler is at the
selected water depth.
¡P Current
Velocity Measuring Equipment
¡V An NE Sensortec A/S UCM-60 current meter or Valeport 108 MKIII current meter or a similar approved
instrument will be used for measuring current direction. Current velocity is measured by
ADCP. Calibration of ADCP is not
likely to be necessary for these instruments as they are calibrated for the
life of the instrument.
The position of the survey vessel will
be positioned to within 3 m of the designated coordinates at each monitoring
station using a differential Global Positional System (dGPS).
All in situ monitoring instruments will be checked, calibrated and
certified by laboratory accredited under HOKLAS or any other international
accreditation scheme before use, and subsequently re-calibrated at three month
intervals throughout the stages of the water quality monitoring. Responses of sensors and electrodes will
be checked with certified standard solutions before each use.
On-site calibration of field equipment
will follow the ¡§Guide to Field and On-
Site Test Methods for the Analysis of Waters¡¨, BS 1427: 2009. Sufficient stocks of spare parts will be
maintained for replacements when necessary. Backup monitoring equipment will also be
made available so that monitoring can proceed uninterrupted even when equipment
is under maintenance, calibration etc.
Water samples for SS measurements will
be collected in high density polythene bottles, packed in ice (cooled to 4¢X C
without being frozen), and delivered to a HOKLAS laboratory as soon as possible
after collection.
At least two replicate samples should
be collected from each of the monitoring events for in situ measurement and lab analysis.
Using
chain of custody forms, collected water samples will be transferred directly to
laboratory for immediate processing of suspended solids, ammonia, nutrients and
BOD5. Water samples will
be analysed for pH and BOD within 4 hours of their arrival at the laboratory. All other parameters will be analysed
within 48 hours of arrival. During
this period samples will be held at 4 ¡Ó 2ºC. Prior to subjecting the sample to metals
analysis, samples will be filtered to remove solids and colloidal matter. Filtration will be accomplished using
acid washed, single-use 0.45 micron membrane filters within a maximum of 8
hours from sample collection. Where
necessary, samples will undergo further preparation involving preconcentration which allows lower method detection limits
to be achieved and removes some of the possible sources of interference.
Field
logs will be maintained for all survey work, noting the date of the survey,
equipment used, survey manager and a record of all activities and
observations. Field logs will be
retained for the duration of the Project and archived on completion.
In situ measured data will be digitally
recorded from the instruments and converted into Microsoft Excel format, or
manually noted. Both disc copy and
hard copy will be retained for the file records. Any deviation from the standard
procedure will be noted in the log and the reason for the deviation
recorded. In addition, field logs
will contain notes of events or activities in the vicinity of the monitoring
location which might give rise to anomalous data being recorded.
The
sampling, collection, storage and identification procedures are described in Section 3.6 of this Manual and the
monitoring team will record all data from in
situ testing and from any analysis carried out on the boat in a Field
Log. All samples will be identified
with a unique date/ time/ location/ depth/ sample type code which will be
attached to the sample container or written in indelible ink directly on the
container. In order to avoid
contamination of the samples, all containers will be new and unused and of
analytical grade quality. Sources
of contamination will be isolated from the working area (for example, vessel
fuel and exhaust fames) and any sample contaminated by local material (such as
printed circuit boards) will be discarded and the sampling repeated. Low level metal analysis in seawater is
easily contaminated through inappropriate handling and sampling techniques. Site staff involved in seawater sample
collection intended for dissolved metal analysis will ensure that they wear
non-contaminating disposable gloves if they have previously been operating or
have handled metallic equipment.
All
in situ monitoring instruments will
be checked, calibrated and certified and subsequently re-calibrated at three
monthly intervals throughout all stages of the water quality monitoring, or as
required by the manufactures specification. Certificate(s) of Calibration specifying
the instrument will be attached to the monitoring reports.
All
samples transferred from one sub-contractor to another will be accompanied by
Chain of Custody (COC) forms. Any
missing or damaged samples require notification to ET Leader following logging in
the laboratory QA system. The
number of samples, the parameters to be tested and the time of delivery should
be clearly stated on the COC forms to ensure that samples are analysed for the
correct parameters and suitable time is provided to the analytical laboratory
for provision of resources required in the analyses.
For
details of the contaminants to be tested, the methods to be used, the
accreditation status of laboratory analytical methods, instruments and
procedures to be used, sample preparation information, method detection limits
(MDLs), QA/QC protocols and turnaround times, the monitoring team will refer to
the previous monitoring programme for the ESC CMPIV and CMPV. The analytical techniques to be adopted
for this Project must conform to HOKLAS (or similar overseas) accreditation.
Data
Quality Objectives (DQOs) have been developed in the previous monitoring
programme for ESC CMPIV and CMPV ([11]) ([12])
to address precision,
accuracy and analyte recovery. The monitoring team is recommended to
follow the DQOs developed for data analysis.
As the QA/QC procedures for the in-situ measurement of DO and Turbidity,
where the difference in value between the first and subsequent measurements at
a certain depth is more than 25% of the value of the first measurement, the
measurements should be discarded and further measurements should be taken to
confirm the values.
Details
of quality control specifications for inorganic testing should be included in
the updated EM&A Manual prior to commencement of disposal activities.
Duplicates
(1 in every 20 samples) will be used to monitoring the precision of the
analysis. Results should be flagged
for reference when:
¡P In water samples, for metals with a
concentration >4x MDL, the duplicate results have more than a 15% RPD
¡P For all analytes
with concentration <4x MDL, the duplicate results will be reported as
analysed and no bounds should be quoted
Standard
and certified reference material (CRM) will be used to monitor accuracy and precision within and
between batches: Results should be flagged
for reference if:
¡P The variation of the standard from its
true value is more than ¡Ó 15% (for mercury: ¡Ó 20%)
Post
digest spikes will be used to determine the recovery of determinants in complex
sample matrices. Results should be
rejected if:
¡P Spike recoveries are more than ¡Ó 25%
from the theoretical recovery for water samples. An exceptional case would be if the
sample concentration is greater than four times the spike value, the spike may
be disregarded.
In
accordance with the recommendations of the EIA for this Project, a monitoring
programme examining sediment quality will be instituted to verify the EIA
predictions and confirm that there is no build-up in contamination adjacent to
the pits. Sediment chemistry has
long been an important component of monitoring programmes at the East of Sha
Chau mud disposal complex. A
comprehensive list of Contaminants of Concern (COCs) has been used since 1997,
comprising eight heavy metals and one metalloid, polycyclic aromatic
hydrocarbons (PAHs), polychlorinated biphenyls (PCBs), organochlorine
pesticides (eg DDT) and Tributyltin (TBT). These contaminants (which correspond to
the list of COCs in ETWB TC(W) 34/2002 in sediments should be measured in the
present monitoring programme and changes over time and distance should also be
examined.
The
main objective of this task is to determine if there are any changes and/or
trends in the concentrations of contaminants in sediments adjacent to the pits
caused by disposal activities at the SB Facility. This objective is most appropriately
addressed through two separate but intrinsically linked sub-tasks:
¡P Pit
Specific Monitoring of Sediment Quality - conducted to examine near field impacts of backfilling
operations at SB on the spread of contaminants from the pits and to allow for
rapid detection of any unacceptable environmental impacts and, if necessary,
changes to the operations plan.
¡P Cumulative
Impact Monitoring of Sediment Quality
- conducted to analyse the ambient conditions in the
The
impact hypothesis for this task is as follows:
There is no increase in
sediment contaminant concentrations over time at individual stations or a trend
of increasing concentrations with proximity to the active pit.
As
a result of the separation of this programme into two sub-tasks, two sets of
null hypotheses should be tested:
Pit Specific Monitoring
of Sediment Quality
H0 There is no increase in sediment
contaminant concentration in the area adjacent to the pits during contaminated
mud disposal works.
Cumulative
Impact Monitoring of Sediment Quality
H0 There is no increase in sediment
contaminant concentration over time in the area of contaminated mud disposal
activity.
H0 There is no increase in sediment
contaminant concentration with proximity to the active pits.
The
designs for assessing the impacts of disposal of contaminated sediment in the
active pits at SB on the sediment chemistry of remote and adjacent areas take into
account the following factors:
¡P The null hypotheses being tested;
¡P Background levels of contaminants in
the region;
¡P Predictions on sediment plume
locations;
¡P Spatial variability in sediment
chemistry;
¡P Temporal variability in sediment
chemistry; and,
¡P Expected statistical treatment of the
data.
This
EM&A Manual is an evolving document that should be updated to maintain its
relevance as the Project progresses.
This includes the relocation of monitoring stations, if considered
appropriate, to best suit the requirements of the monitoring programme and to
take into account other work that is occurring in the direct vicinity of the
active facility.
The
parameters that should be measured in sediments collected during the two sub-tasks
and the rationale for each are given below. Some of the contaminants listed are the
"Contaminants of Concern" for which Lower and Upper Chemical
Exceedance Limits (LCEL/UCEL) exist.
a)
Total Organic Carbon (TOC) - an indicator of organic load and
the impact on bottom layer dissolved oxygen. TOC is an important factor influencing
the chemical partitioning and toxicity of hydrophobic organic compounds such as
PAHs, PCBs and pesticides. High TOC
often infers that hydrophobic contaminants are less bioavailable;
b)
Inorganic Contaminants - metals and metalloids present in
the disposed sediments which may be bioaccumulated;
c)
Polycyclic Aromatic Hydrocarbons (PAH) - a class of organic compounds some
of which are persistent and carcinogenic.
These compounds may be bioaccumulated and
stored in the fatty body tissues of marine mammals;
d)
Total Polychlorinated Biphenyls (PCB) - a class of persistent man-made
chemicals which tend to bioaccumulate through the
food chain and can cause reproductive failure and cancer;
e)
Organochlorine
Pesticides (DDE & DDT)
- contaminants which are persistent, highly lipophilic (can be accumulated and
stored in fat), have high bioaccumulation and biomagnification
potential, and high toxicity to aquatic organisms;
f)
Tributyltin (TBT) (in sediment and
interstitial water) ¡V
moderately persistent toxic compound found in marine sediments which may be bioaccumulated and cause growth abnormalities and
reproductive failure; and
g)
Percentage of Silt/Clay (% < 63£gm) ¡V measured in Cumulative Impacts
Monitoring only. Organic
contaminants and metals bind more readily to finer particles than coarser
particles due to their larger surface area and consequent larger number of
binding sites.
Pit
specific monitoring of sediment quality will be undertaken during backfilling
activities. Sediment samples will
be collected from two stations in the active pit, two stations on the edge of
the active pit and two stations in close proximity to the pit. For pit specific monitoring, parameters
(a) to (f) in Section 4.4.1 will be
analysed.
Sediment
samples will be collected on a monthly basis from any of the six stations shown
in Figure 4.1 and Table
4.1. Locations of the six
sampling stations will be dependent on the location of the active pit and will
be adjusted accordingly. For
example, when SB CMP 1 is active, stations SB-NNAA-B, SB ¡VNEAA-B and SB -NPAA-B
will be monitored. Twelve
replicates of composite samples (i.e. 5 grab samples obtained using a cluster
grab) will be collected from each of the stations. The sampling frequency and number of
replicates are the same as those currently proposed for the CMP V EM&A
programme and will initially be used for SB monitoring as a consistent and
conservative approach. These will
be reviewed and adjusted accordingly based on power analyses in each Annual Review Report.
Table 4.1 Coordinates
of Pit Specific Sediment Monitoring Stations
Monitoring Stations |
Easting |
Northing |
SB CMP 1 Active |
|
|
Near-Pit |
|
|
SB-NNAA |
813945 |
819657 |
SB-NNAB |
816218 |
819650 |
Pit-Edge |
|
|
SB-NEAA |
814380 |
819657 |
SB-NEAB |
815775 |
819650 |
Active-Pit |
|
|
SB-NPAA |
814901 |
819650 |
SB-NPAB |
815324 |
819650 |
SB CMP 2 Active |
|
|
Near-Pit |
|
|
SB-NNBA |
813580 |
819005 |
SB-NNBB |
815790 |
818990 |
Pit-Edge |
|
|
SB-NEBA |
814067 |
819005 |
SB-NEBB |
815404 |
818997 |
Active-Pit |
|
|
SB-NPBA |
814587 |
819005 |
SB-NPBB |
814982 |
819001 |
Note:
Coordinates are based on
Sediment
samples should be collected from stations located in four discrete areas, with two
stations in each area. The areas
should be located at increasing distances from the disposal operations (ie. Near Field, Mid Field, Capped Pits
and Far Field). Sediment
samples should also be collected from the Ma Wan and Tai Ho Bay monitoring
stations. For cumulative impacts
monitoring parameters (a) to (g) in Section
4.4.1 will be analysed.
Sediment
samples will be collected four times per year, twice during the dry season and
twice during the wet season at stations indicated on Figure 4.2
and the coordinates are shown in Table
4.2. Twelve replicates of
composite samples (i.e. 5 grab samples obtained using a cluster grab) will be
collected from each station. The
sampling frequency and number of replicates are the same as those currently
proposed for the CMP V EM&A programme and will initially be used for SB
monitoring as a consistent and conservative approach. These will be reviewed and adjusted
accordingly based on power analyses in each Annual
Review Report.
Table 4.2 Coordinates
of Cumulative Impact Sediment Monitoring Stations
Monitoring Stations |
Easting |
Northing |
Near-field |
|
|
SB-RNA |
813067 |
820942 |
SB-RNB |
818158 |
821226 |
Mid-field |
|
|
SB-RMA |
810491 |
823152 |
SB-RMB |
821078 |
822747 |
Far-field |
|
|
SB-RFA |
805928 |
827614 |
SB-RFB |
806435 |
816662 |
Capped Pits |
|
|
SB-RCA |
809024 |
821205 |
SB-RCB |
809268 |
820942 |
Sensitive Receiver
Stations |
|
|
MW1 |
823603 |
823653 |
THB1 |
814514 |
817932 |
THB2 |
815873 |
818035 |
Note:
Coordinates are based on
Observed
differences in the levels of contaminants will be tested using analysis of
variance (ANOVA) with factors area and station, followed by Student Newman Keuls (SNK) multiple comparison procedures to isolate which
levels within the factor(s) differ from others.
For
all of the ANOVA techniques performed during the monitoring programme, initial
analyses should be performed to ensure that the data complies with the specific
assumptions of ANOVA. These
assumptions state:
¡P the data within and among samples must
be independent of each other;
¡P the variance within samples must be
equal (tested through the use of tests such as Levene's
median test); and,
¡P the data among the samples must be
normally distributed (tested through the use of tests such as the Kolgomorov-Smirnov test).
Should
the data not comply with these assumptions then appropriate transformation
should be applied to the data (eg, arc-sin for
percentage data, log (x+1) for abundance data, or rank transformation if
necessary). If, after
transformation, the data are still non-compliant then non-parametric tests
equivalent to ANOVA such as Kruskal-Wallis tests
should be used.
The
design of the monitoring programme should allow nested ANOVA techniques to be
employed. These techniques will be
used to analyse the data at different spatial and temporal scales of
replication. Statistical
differences should be tested at the following factors: between areas and
between sampling times. An
advantage of this sampling design is that it removes the possibility of
detecting differences simply due to inherent variation over spatial scales in
the active area and thus facilitates clearer attribution to disposal
operations. By replicating within
each area, ie by sampling two stations in one area,
any statistically significant differences detected between areas are more
likely to be due to factors other than spatial variation (eg
locations of disposal operations).
This approach is now an internationally recommended technique for use in
monitoring programmes ([13]).
Multidimensional scaling ordination techniques will also be applied to
the data, if deemed necessary.
Should
significant increases be detected in the level of contaminants in sediment
samples over time or proximity to the active pits, a review of the other
monitoring parameters should be undertaken. This review will focus on sampling
stations in the vicinity of the sediment quality monitoring stations where
increases are detected to see if these can be attributed to contaminant
migration from the active pits.
Assessment of the statistical significance of the data, confidence in
the data and the presence of supporting data from other components of the
monitoring programme should be jointly assessed. If appropriate, changes to the
operations plan should be considered.
All
samples should be collected by an experienced sampling team, deployed on a
survey boat equipped with fully calibrated sampling equipment and precision
navigational instruments. All
vessel positioning should be accomplished with a calibrated Differential Global
Positioning System (dGPS), ensuring station location
accuracy to < ¡Ó 1 m (95% confidence), with sample position automatically
logged and mapped by the navigation computer. Where sample stations are located in
close proximity to the pit area, positioning should be further validated by use
of an echo sounder to detect whether the vessel is within the boundaries of the
pit.
At
each sampling station the top 5 cm of seabed sediment should be collected using
a 5-component cluster grab sampler which collects surface sediments with a
minimal disruption to the surface layer and is designed to work effectively in
soft sediment such as those found in the area. The cluster grab should be deployed once
at each of the stations located within each sampling area (eg
Pit-Edge). The grabs can be
customised and a fine mesh lid added, which ensures that the fine fluid
sediments on the surface of the seabed are retained in the sample. Utilisation of this cluster sampler
allows a large volume of sediment to be collected in a single deployment. Other similar samplers (eg Petit-ponar) collect less
sediment in each deployment may have difficulty in collecting adequate samples
in soft sediments, such as those within the study area, thereby reducing
efficiency and increasing collection time.
The five-cluster grab should be collected and combined, and the sample,
labelled, double-bagged and stored in an ice chest cooled to a temperature of 4¢XC with ice packs. The sediment sampler and all other
utensils should be rinsed with seawater after each sample has been collected to
avoid cross contamination between samples.
On completion of the survey, all samples should be promptly transported,
in chilled containers, to the testing laboratory for analysis.
A
broad range of contaminants should be analysed in sediment samples including
metals, metalloids, PAHs, PCBs, pesticides and Tributyltin in both sediment and
interstitial water. The method
detection limits should be consistent with previous monitoring programmes at
East of Sha Chau. Other QA/QC
procedures to be implemented for marine sediment analyses include:
¡P Laboratory
blanks - an analyte free matrix to which all reagents will be added in
the same volumes or proportions as used in the standard sample preparation to
monitor contamination introduced in the laboratory (organics and inorganics);
¡P Batch
duplicates - an intralaboratory split sample randomly selected from the
sample batch to monitor method precision (intrabatch)
in a given sample matrix (inorganics only);
¡P Certified
Reference Materials -
analysis of a material with a known concentration of contamination to determine
the accuracy of results in a given matrix (inorganics only);
¡P Single
Control Samples - a
known, interference-free matrix spiked with target analytes
used to monitor laboratory preparation techniques (organics only);
¡P Duplicate
Control Samples -
multiple single control samples designed to monitor preparation technique reproducibility
(organics).
Data
Quality Objectives (DQOs) have been developed to address precision, accuracy
and analyte recovery.
Duplicates
(1 in every 20 samples) should be used to monitoring the precision of the
analysis. Results should be flagged
for reference when:
¡P For all analytes,
except metals, with concentration >4x Method Detection Limit (MDL), the
duplicate results have more than a 20% Relative Percentage Deviation (RPD)
¡P In water samples, for metals with a
concentration >4x MDL, the duplicate results have more than a 15% RPD
¡P In sediment and biota samples, for
metals with a concentration >4x MDL, the duplicate results have more than a
25% RPD
¡P For all analytes
with concentration <4x MDL, the duplicate results should be reported as
analysed and no bounds should be quoted
Standard
and certified reference material (CRM) will be used to monitor accuracy and
precision within and between batches: Results should be flagged for reference
if:
¡P The variation of the standard from its
true value is more than ¡Ó 15% (for mercury: ¡Ó 20%).
Post
digest spikes should be used to determine the recovery of determinants in
complex sample matrices. Results
should be rejected if:
¡P Spike recoveries are more than ¡Ó 25%
from the theoretical recovery for waters, sediment and marine biota. An exceptional case would be if the
sample concentration is greater than four times the spike value, the spike may
be disregarded.
Samples
should be analysed in lots of less than 20. In order to measure the laboratory
performance within each batch of samples, a single control sample (SCS), a
duplicate control sample (DCS) and a method blank (MB) should be processed
concurrently with the samples. A
SCS or DCS consists of an interference free control matrix that is spiked with
a group of target compounds representative of the method analytes.
Method
blanks, also known as reagent, analytical, or preparation blanks, should be
analysed to assess the level of contamination that exist in the analytical
system and which might lead to the reporting of elevated concentration levels
or false positive data. For organic
analyses, the concentration of target analytes in the
blank must be below the reporting limit for that analyte
in order for the blank to be considered acceptable.
Accuracy
is expressed as the average percent recovery for the SCS and precision is
expressed as the relative percent difference (RPD) for the DCS pair. For control limits that are not
established due to insufficient data sets, the QC Acceptance Criteria of US EPA
Method 8080 and 8270A should be used as a supplement. Once enough data are collected, the
in-house control limits should then be calculated.
The
accuracy and precision data for SCS and DCS should be evaluated against
laboratory established control limits.
QC results falling outside the control limits should be automatically
flagged. The acceptance criterion
is that 100 percent of the precision and accuracy values must fall within the
control limits. If this criterion
is not met, corrective action must be taken. This may include repeat sample analysis.
The
average percent recovery of the SCS should be compared to the limit set for
each compound being monitored (Table 4.3). For DCS, an RPD of less than 20% is
deemed to be acceptable in normal instances.
For
multianalyte organic tests, if greater than 20% of
the accuracy or precision results for the SCS/DCS are outside of the control
limits, the data are considered suspect and the samples associated with the
unacceptable DCS are reprepared and/or reanalysed.
Table 4.3 Quality
Control Acceptance Criteria for Organics Analyses
Target Analytes |
Percent
Recovery Measured |
Naphthalene |
74 - 126 |
Acenaphthalene |
69 - 125 |
Acenaphthene |
73 - 119 |
Fluorene |
81 - 129 |
Phenanthrene |
74 - 131 |
Anthracene |
63 - 116 |
Fluoranthene |
73 - 134 |
Pyrene |
59 - 129 |
Benzo(a)anthracene |
77 - 136 |
Chrysene |
53 - 130 |
Benzo(a)pyrene |
51 - 103 |
Dibenzo(a,h)anthracene |
78 - 126 |
DDE |
73 - 121 |
DDT |
87 - 120 |
Total
PCBs |
79 - 127 |
Tributyltin |
80 - 115 |
Results
must be greater than zero
The
ecotoxicological testing programme will feature a
suite of tests that include three phylogenetically distinct species that
interact with bedded sediments in different ways. Unacceptable impacts may have occurred
if the levels of contaminants in the sediments collected in the adjacent area
of the active pits are shown to have caused toxicity to marine fauna. The findings of the sediment toxicity
tests will be compared to the results of the sediments chemistry.
The
objective of this task is to determine if there are any changes and/or trends
caused by backfilling activities in the toxicity of sediments adjacent to the
pits as a result of backfilling activities.
In
accordance with the objectives of this EM&A programme, the impact
hypothesis for this task will be as follows:
There is no increase in
sediment toxicity over time at individual stations or a trend of increasing
toxicity with proximity to the pit.
The
null hypothesis which should be statistically tested is as follows:
H0 There are no differences in the
toxicity of sediments collected at stations adjacent to the active pits when
compared with reference sediments.
In
order to determine whether contaminated sediment placed in the active pit
represents an ecological risk to biota in areas adjacent to the mud pit, ecotoxicological evaluations will be performed on sediment
collected from these surrounding areas.
The
toxicological testing programme should feature a suite of tests that includes
phylogenetically distinct species which interact with sediments in different
ways. The testing programme will
include whole-sediment, or solid-phase toxicity tests. The following three international
species should be tested:
¡P Burrowing amphipod (Leptocheirus plumulosus, Ampelisca abdita, Eohaustorius estuarius or
other equivalent species);
¡P Burrowing polychaete (Neanthes arenaceodentata
or other equivalent species); and,
¡P Free swimming larvae of bivalves (Crassostrea gigas, Mytilus spp. or
other equivalent species).
In
addition, two of the following local species should also be tested:
¡P Amphipod Melita longidactyla;
¡P Polychaete Capitella capitata;
¡P Juvenile shrimp Metapenaeus ensis or Penaeus (Litopenaeus) vannamei;
and,
¡P Barnacle larvae Balanus amphitrite.
The
experimental designs for assessing the impacts of disposal of contaminated
sediment at SB on the toxicity of sediments in remote and adjacent areas take
into account the following factors:
¡P The null hypotheses being tested;
¡P Location of other potential sources of
contaminants in the North Lantau region, eg,
¡P Predictions taken from the EIA on
sediment plume locations; and,
¡P Expected statistical treatment of the
data.
Once the pit is
active (ie receiving contaminated sediment), sediment
toxicity testing will be performed only when the level(s) of sediment
contaminant(s) in the Near-field station(s) exceed the LCELs as measured by the
Cumulative Impact Monitoring of Sediment
Quality. Monitoring stations
will be sampled not more than twice per year (once in each of the wet and dry
seasons).
Sediment
samples will be collected from two treatment areas as well as at the Ma Wan and
Tai Ho Bay stations. The first
treatment area is represented by samples taken from two stations in an area
close to the active pits (Near-Field) and the second treatment area is
represented by samples collected from stations in a reference area
(Far-Field). The locations of
stations are shown in Figure 5.1 and the
coordinates are presented in Table 5.1. Five replicates of composite samples
will be collected from each of the stations and used for the sediment toxicity
tests. The sampling frequency and
number of replicates are the same as those currently proposed for the CMP V
EM&A programme and will initially be used for SB monitoring as a consistent
and conservative approach. These
will be reviewed and adjusted accordingly based on power analyses in each Annual Review Report. In addition, locations of sampling
stations will be amended based on location of the active pit.
Table 5.1 Sediment
Toxicity Testing Sampling Stations
Station |
Easting |
Northing |
SB CMP 1 Active |
|
|
Reference |
|
|
SB-TRA |
806358 |
827343 |
SB-TRB |
806465 |
816513 |
Near-Field |
|
|
SB-TAA |
814685 |
820017 |
SB-TAB |
815797 |
819269 |
Sensitive Receiver
Stations |
|
|
MW1 |
823603 |
823653 |
THB1 |
814514 |
817932 |
THB2 |
815873 |
818035 |
SB CMP 2 Active |
|
|
Reference |
|
|
SB-TRA |
806358 |
827343 |
SB-TRB |
806465 |
816513 |
Near-Field |
|
|
SB-TBA |
813954 |
819131 |
SB-TBB |
814960 |
818327 |
Sensitive Receiver
Stations |
|
|
MW1 |
823603 |
823653 |
THB1 |
814514 |
817932 |
THB2 |
815873 |
818035 |
Note:
Coordinates are based on
Each
of the toxicological tests will be evaluated for statistically significant
increases in toxicity.
Statistically significant toxicity will be determined by performing an
analysis of variance (ANOVA) test that compares the responses observed in the
test treatments with those of the reference treatments. At the end of the monitoring programme
changes in the toxicity of the sediments over time will be evaluated through
the use of ANOVA incorporating both spatial and temporal scales of variation.
Once
the data have been evaluated for significance, it is important to identify
potential causes of toxicity and the biological significance of the observed
effects. The cause of the observed
effects needs to be distinguished between 1) non-persistent contaminants, 2)
persistent contaminants, and 3) physical factors. It is most important to determine if the
cause of the toxicity is due to persistent contaminants that are derived from
the contaminated sediment placed in the pits (eg
metals, pesticides, PAHs, TBT), to non-persistent contaminants (eg sulfides, ammonia, salinity)
or to physical factors (eg grain size).
If
the toxicity is due to persistent contaminants that are associated with
disposal operations, the operations plan for the active pits may not be
effective enough at managing the containment of contaminated sediment to
acceptable levels and thus should be modified. If the observed toxicity is due to
non-persistent contaminants, the effects may be due to the pit but they are
transient. The toxicity of these
types of contaminants can be assimilated by the environment in relatively short
time periods, and are thus less harmful.
If the effects are related to physical factors, they are again of less
concern and would not likely require changes in the facility operations plan.
As
non-contaminant factors and physical factors can confound toxicity test
interpretation, the ET will monitor ammonia, sulfides,
interstitial salinity, and sediment-grain size. Each of these factors has been observed
to elicit a toxic response in test organisms, however, they are not factors
related to persistent contaminants of concern. This information will be used to investigate
any observed toxicity responses and determine whether the response is due to
persistent contaminants or to more transient factors.
The
amphipod toxicity test with burrowing amphipod (Leptocheirus plumulosus, Ampelisca
abdita, Eohaustorius estuarius or other equivalent species as agreed with
EPD/AFCD prior to conduct of the toxicity test) will evaluate survival
following a 10-day exposure to test sediment. Procedures will follow those outlined in
PSEP (1995) ([14])
and/or USEPA (1994) ([15]), depending on the species used for
the test, and CEDD's Environmental Laboratory Guidance Document (1996) ([16]).
The amphipod test will be conducted as a static test and will be
performed with 175 ml of sediment and 800 ml of overlying seawater placed in a
1-L glass jar. At test initiation,
each of five replicate test chambers will be seeded with 20 amphipods. Test chambers will be maintained at 20¢XC
and will be checked daily throughout the test to establish trends in sediment
avoidance. After the 10-day
exposure, the benthic tests will be terminated by sieving the sediments and
enumerating the live and dead amphipods.
The
test on Neanthes arenaceodentata
(or an equivalent species as agreed with EPD/AFCD prior to conduct of the
toxicity test) will evaluate polychaete survival and growth following a 20-day
exposure to test sediment. Test
methods will follow those outlined in PSEP (1995) ([17]).
The test will be conducted as a static test, performed in 175 ml of
sediment and 800 ml of overlying seawater in 1-L glass jars. At test initiation, each of five
replicate test chambers will be seeded with five polychaetes. Test chambers will be maintained at 20¢XC
and will be checked daily to record mortality and sediment avoidance. To promote growth, worms will be fed TetraMarin every third day throughout the test. After 20 days, the N. arenaceodentata test will be
terminated by sieving each test chamber and enumerating both live and dead
organisms. Surviving polychaetes
will be dried and weighed for each test chamber. Average dry weight will be compared to
initial biomass to determine mean growth for each test chamber.
The
larval-development toxicity test will be performed with fertilized bivalve
embryos (Crassostrea gigas, Mytilus spp. or a equivalent
species as agreed with EPD/AFCD prior to conduct of the toxicity test) will
evaluate larval survival and development following a 48 to 96-hour exposure to
test sediments. This procedure will
follow those outlined in PSEP (1995) ([18]).
This test will be conducted in 20 mg of test sediment with 800 ml of
seawater in 1-L glass jars. At test
initiation, test jars will be seeded with 20 to 40 embryos per ml. Test chambers will be maintained at
16¢XC. At termination, overlying
water will be decanted and subsamples drawn from the supernatant. Survival and normal larval development
will then be determined under an inverted compound microscope.
In
each of the sediment tests, a sediment/seawater control (consisting of clean
sediment for amphipod and polychaete or clean seawater for the bivalve larval
test) will be tested concurrently with the test sediments. The control treatment should be included
to determine the health of the test organisms. Sediments collected from the reference
stations will also be tested concurrently with test sediments to provide a
basis for statistical comparison.
For the larval tests, grain-size controls will be tested concurrently
with the test sediments to discern any effects related to sediment grain
size. Additionally, a water-only
reference toxicant test using cadmium (from CdCl2) or copper (from
CuNO3) will be conducted with each batch of test organisms. This reference-toxicant test provides a
measure of relative sensitivity for each group of test organisms. All toxicity tests will be completed and
reported within four months from collection of the samples.
Procedures
for sampling will be as for the sediment chemistry for Sediment Quality
Monitoring as detailed in Section 4.7
of this Manual. Shipments of the
sediments will be packaged in ice-boxes in order to maintain the sediments at a
constant temperature of 4oC and dispatched by express courier for
immediate testing.
To
ensure the quality and integrity of the ecotoxicological
data and subsequent analyses, a QA/QC control program will be followed that
meets or exceeds the QA/QC program outlined in Chapter 4 of CEDD's
Environmental Laboratory Guidance Document (1996). The QA/QC program for the facility ecotoxicological program is described below.
Upon
sample receipt, samples will be held at 4¢X ¡Ó 2¢X C in the dark until required
for testing. Sediment holding times
for biological testing begin the day of sample collection and will be kept at a
minimum. The holding time for
sediment intended for biological testing will be eight weeks. Chain-of custody forms will accompany
each batch of samples to track samples and to provide temperature data before
and after shipping.
Clean
seawater for holding test organisms will be sand-filtered seawater piped
directly into the testing laboratory.
Seawater used for test water and control water should be additionally
gravity-feed filtered through a 0.45 micron filter before use for all test
species. Bioassay seawater should
be continually monitored for water quality and the presence of algal blooms.
Procedures
for calibration and maintenance of water quality equipment will follow
Measurement Standards Laboratory (MSL) protocols. All measuring and testing equipment used
on this Project should be traceable to the data collected and should be
calibrated before use.
The
pH meters used for obtaining water quality data must be calibrated daily before
use according to MSL-M-045, Calibration and Use of pH Meters. The calibration will be documented on
the pH Meter Calibration Record sheet.
Maintenance on pH meters will be performed monthly. Maintenance should include visual
inspection, cleaning probes in 0.1 M HCl, and
cleaning any corroded contacts.
Refractometers
used for obtaining water quality data will be calibrated monthly using IAPO
Standard Seawater according to MSL-M-048, Calibration and Use of
Refractometers. The calibration
should be documented on the Refractometer Calibration Record sheet. Refractometers should be inspected
visually and cleaned monthly.
Digital
thermometer calibrations will be performed monthly by comparison to a certified
mercury thermometer as specified in MSL-M-047, Calibration and Use of
Thermometers. The calibration will
be documented on a Thermometer Calibration Record. Maintenance should include visual
inspection and cleaning of salt and corrosion from connectors and contacts.
Dissolved
oxygen meters should be calibrated daily before use according to MSL-M-046,
Calibration and Use of Dissolved Oxygen Meters. The calibration should be documented on
the Dissolved Oxygen Meter Calibration Record. Maintenance should be performed once
monthly and should include visual inspection, cleaning the probe, and replacing
of probe membrane.
The
Fisher Accumet 1003 pH/selective ion electrode meter
with ammonia electrode should be maintained according to manufacturer¡¦s
instructions. The meter should be
calibrated on each day of use with three concentrations of NH4Cl
standards bracketing the expected test concentrations of ammonia. The ammonia probe should be stored in
0.02 M NH4Cl when not in use.
In
addition to QA/QC mentioned above, a series of reviews by qualified laboratory
personnel should be implemented to ensure that the data generated for this
Project meets the data quality objectives.
These reviews should include the following:
¡P Data should be reviewed periodically
by laboratory personnel to ensure that sample testing activities are completely
and adequately documented.
¡P Sample holding times, sample
integrity, test animal handling and acclimation, equipment calibration, water
quality measurements, reference toxicity results, observations, and control
survival will be reviewed by qualified laboratory personnel. The results of QC measurements will be
compared to pre-established criteria as a measure of data acceptability.
¡P A final data audit by the Quality
Assurance Officer will be performed prior to submission of the data and
report. This audit will ensure that
the data are accurate, traceable, defensible, and complete, as compared to the
Manual. The audit procedure
(MSL-Q-005, Quality Assurance Data Audits) is a statistical, randomized check
which involves comparing selected reported values to the original data. This procedure is designed to ensure a
95 percent chance of detecting whether one percent or more reported values
disagree with the original data.
The overall
quality assurance objective for this Project is to implement procedures that
will ensure the collection of representative data that is of acceptable and
defensible quality. The data
quality objectives for the ecotoxicological tests
will be devised with reference to the previous data quality objectives
established for the previous monitoring programmes for the East of Sha Chau
CMPs.
A negative
control provides a measure of test organism health. Negative control treatment will be running
concurrent to each toxicity test as a measure of the test organism's
health. For the amphipod (eg Ampelisca sp.) and polychaete (eg Neanthes sp.) toxicity tests, the negative
control should consist of clean, native sediment that is to be collected from
the test organism's natural habitat.
For the bivalve larval test, the negative control should consist of
clean seawater. Acceptable limits
for the negative controls will be defined with reference to the limits
established for the East of Sha Chau CMP monitoring programmes. If survival or normal development do not
meet the acceptability criteria, all data should be evaluated and the test may
need to be repeated.
Water quality
measurements provide documentation of environmental conditions within the test
chambers during the exposure.
Temperature, dissolved oxygen, pH, and salinity will be measured daily
throughout the test. Conditions
that are acceptable to maintain the health of the test organisms will be
defined with reference to the acceptable conditions defined for the East of Sha
Chau CMP monitoring programmes. If
test conditions are outside the acceptability criteria, the data will need to
be qualified.
The positive
control provides a relative measure of test organism sensitivity. For each of the bioassays for the active
pits, a separate reference-toxicant test should be performed with each batch of
test organisms. The results of the
reference-toxicant tests will be compared with control charts generated by the
testing laboratory for that species and toxicant. Those results within two standard
deviations of the cumulative mean are considered to be similar in sensitivity
to previous test populations. For amphipods
(eg A. abdita) the reference-toxicant test will be performed
with cadmium in the form of cadmium chloride (CdCl2); for
polychaetes (eg N.
arenaceodentata) and bivalve larvae
reference-toxicant tests will be performed with copper as copper nitrate (CuNO3). If the test results are outside the
control limits, the data will need to be qualified.
The
bioaccumulation of contaminants by prey organisms and consequent biomagnification of contaminants up the food chain has long
been an issue of concern for the disposal of contaminated sediment at East of
Sha Chau. Although the public at
large may not appreciate the technical details of a biomonitoring
programme, especially concerning mobile populations, they are well aware of the
potential for contaminated sediment disposal to taint seafood products. In recognition of these issues, a
comprehensive biomonitoring programme which will
address public concerns about contamination of seafood in the area through use
of the data in a risk assessment framework should be undertaken for the
backfilling activities at the active pits.
As
well as examining the influence of contaminated sediment disposal on
contaminant levels in demersal fisheries resources, the impact of disposal on
the abundance and structure of demersal fisheries should also be assessed. Consequently, there are two objectives
for this task:
¡P Biomonitoring of Contaminants - To identify any increases in the
concentrations of contaminants in tissues and whole body burdens of demersal
marine life adjacent to and remote from the active pits.
¡P Trawling,
Sorting & Analysis
- To assess the impact of contaminated sediment disposal at the active pits on
the fisheries resources of the
In
accordance with the predictions of the EIA and the objectives for this EM&A
programme, the impact hypothesis for this task is as follows:
There is no increase in
tissue or whole body contaminant concentration over time in selected target
species.
In
order to reflect the dual workstreams under this
task, two sets of null hypotheses should be tested:
Biomonitoring
of Contaminants
H0
The concentrations of contaminants in
tissue and whole body samples of demersal marine life adjacent to the active
pits are not greater than contaminant concentrations from samples collected at
stations remote from the active pits.
H0
The concentrations of contaminants in
tissue and whole body samples of demersal marine life do not increase over
time.
Trawling,
Sorting & Analysis
H0
There are no differences in the
composition or abundance of demersal fisheries resources near to and remote
from the active pits.
H0
There are no differences in the
composition or abundance of demersal fisheries resources over time.
Samples
for biomonitoring of contaminants will be selected from
trawl samples described in Section 6.4.2. Samples of the target species should be
collected twice per year (July/August in the wet season and January/February in
the dry seasons) specifically from six stations. The reference stations will comprise of
two stations located near Lung Kwu Chau and two
stations to the south west of the airport (Figure 6.1). These reference stations are the same as
those sampled in the ongoing monitoring programme (Agreements No. CE 64/99,
CE 19/2004 and CE 4/2009(EP)). The other two stations will be impact
stations, located on the edge of active pits. However, in order to obtain sufficient
tissue and whole body samples from impact and reference stations, samples
collected at different impact and reference stations will be combined where
necessary.
Due
to concerns regarding the collection of sufficient quantities of target
species, catch from the first trawl survey of each season (trawl for catch
characterisation) should be retained in a frozen state for joint processing with
the biomonitoring samples in the following month.
Five
replicate tows (each with six nets) should be conducted at each station and
composite samples prepared from all nets and tows at each station during each
of the sampling events. Replicate
data points should be obtained whenever the abundance of target species allows
laboratory analysis of more than one tissue/whole body sample for each target
species at each station. The design
to be developed should address the following key issues:
¡P Rigour of the dataset to allow for
statistical testing of observed differences;
¡P Data required for the risk assessment;
¡P Composite samples to minimise the
variance between fish and improve the reliability of detecting any significant
trends; and,
¡P Analysing replicate samples, whenever
possible, to provide cost effective statistical rigour.
The
locations of biota monitoring stations are shown in Figure 6.1
and the coordinates are shown Table 6.1. Details on the Sampling Programme are shown in Annex C. The sampling frequency and number of
replicates are the same as those currently proposed for the CMP V EM&A
programme and will initially be used for SB monitoring as a consistent and
conservative approach.
Table 6.1 Demersal
Trawl Sampling Station Coordinates (Center of the transect)
Station |
Easting |
Northing |
Impact |
|
|
SB-INA |
814304 |
819813 |
SB-INB |
814052 |
818459 |
Reference North |
|
|
TNA |
806627 |
827674 |
TNB |
807040 |
825248 |
Reference South |
|
|
TSA |
806366 |
816977 |
TSB |
805796 |
815951 |
Note:
Coordinates are based on
The
design of the sampling programme should encompass the following key issues:
¡P Temporal variation in fisheries
assemblages; and,
¡P Spatial variation of mobile
assemblages of demersal fisheries resources.
Samples should
be collected for analysis four times each year (twice in the dry season and
twice in the wet season) to account for temporal variation in the fisheries
assemblages. The samples should be
collected from 5 replicate trawls (each with 6 nets) undertaken along a transect at each of the six stations, in which two
stations are located at the impact area while four stations are located at the
two reference areas (Figure 6.1). The sampling frequency and number of
replicates are the same as those currently proposed for the CMP V EM&A
programme and will initially be used for SB monitoring as a consistent and
conservative approach. Samples for biomonitoring of contaminants will be selected from the
trawl samples.
The
data should be analysed using analysis of variance (ANOVA) techniques to test
for differences between the two sampling sites (Impact and Reference). Once a time series of data (sequential
sampling events) has been gathered, differences should be tested between sites
and between the different sampling events to examine any temporal trends in
contaminant levels in the target species.
Catch
composition should be analysed using analysis of variance (ANOVA) techniques to
account for changes in catches between and within sites in the
If
significant increases are detected in the levels of contaminants in fisheries
resources in this programme it will indicate that bioaccumulation is
occurring. However,
as demersal fisheries resources are generally mobile (except burrowing species
such as the gobies Trypauchen
and Oxyurichthys),
increases may not necessarily be due to backfilling at the SB Facility. Other contaminant sources such as
discharges from the Pearl River, local sewage outfalls or non-point source
pollution may cause such increases.
To account for these confounding effects, the results from this
Project¡¦s sediment and water quality monitoring programmes along with the most
recent sediment toxicity test results will be examined so that the sources of
any increases can be identified.
Should there be evidence that effects are due to the active facility,
the monitoring and disposal programmes will be reviewed and revised where
necessary as agreed with CEDD and the EPD.
The
contaminants of concern for this Project should be measured separately, firstly
in tissue samples (soft tissue) and secondly in whole body samples obtained
from the species list established for this project. The species to be examined should be
chosen based on two criteria:
¡P The degree to which the organisms are
exposed to contaminants in the sediments; and
¡P The position of the organisms in the
food chain and the trophic level of their predators (ie,
humans or Indo-Pacific Humpback Dolphin).
The
species list (Table 6.3) has been
devised with reference to the previous biomonitoring
programmes for the East of Sha Chau CMP¡¦s.
Comparing to the monitoring programme from February 2006 to April 2009,
the analysis of whole body samples of Cephalopods is suggested to be removed
from the present monitoring programme as according to Jefferson and Hung
(2004) ([19]), there is little evidence that Indo-Pacific
Humpback Dolphin consumed Cephalopods as a major prey item. Therefore, it is considered unnecessary
to analyse Cephalopods for the risk assessment of Indo-Pacific Humpback Dolphin
(please refer to Section 7 for
details of risk assessment).
Table 6.2 List
of Target Species for Tissue and Whole Body Analysis
Type |
Tissue Analysis
Target Taxon |
Alternative Taxon |
Whole Body Analysis
Target Taxon |
Alternative Taxon |
Prawn |
Metapenaeus
ensis |
Metapenaeus joyneri |
Metapenaeus
spp. |
Metapenaeopsis spp. |
|
Metapenaeus Affinis |
Metapenaeopsis spp. |
|
|
Mantis
Shrimp |
Oratosquilla oratoria |
Oratosquillina
interrupta Miyakea
nepa |
Oratosquilla
spp. |
Oratosquillina
spp. |
Swimming
Crab |
Charybdis cruciata |
Portunus sanguinolentus |
|
|
|
|
Scylla serrata |
|
|
|
|
Portunus
pelagicus |
|
|
|
|
Portunus Trituberculatus |
|
|
Flat
Fish |
Cynoglossus macrolepidotus |
Cynoglossus trigrammus and Solea
ovate |
|
|
Burrowing
Fish |
Trypauchen
vagina |
Oxyurichthys Tentacularis |
|
|
Demersal/Pelagic Fish |
Leiognathus brevirostris |
Collichthys
lucida |
Leiognathus
spp. |
|
|
|
|
Collichthys
lucida |
Johnius
belengeri |
|
|
|
|
Other
Sciaenidae |
Gastropod |
Turritella
terbra |
|
|
|
Non-Commercial Crab |
|
|
Charybdis spp. |
|
Note:
¡P
In
case sufficient samples of the target species cannot be obtained, analysis of
the alternative species should be carried out.
¡P
The
alternative species are listed in order of priority.
In
the laboratory, each trawl sample should be sorted for target species and
target species selection should be based on the abundance and potential sample
mass available for each species captured.
In preparing composite samples for analysis, different species will not
be mixed. Each composite sample for
laboratory analysis should consist of three or more organisms, with priority
given to larger individuals with no more than 2 fold difference in length. Length and weight of all individual
organisms represented by the composite sample will be recorded and individuals
for tissue sample analysis dissected with a sterilised (with hexane) titanium
knife and a composite sample prepared.
Care should be taken not to cross contaminate any tissue samples with
gut contents. For fish, the axial
muscle should be extracted for analysis.
For prawn/shrimp and crab, abdominal and claw/leg muscle should be used,
respectively. For gastropods,
tissue samples should be taken from the soft body tissue.
The
analytical parameters for tissue and whole body testing are given below:
¡P Inorganic Arsenic;
¡P Cadmium;
¡P Chromium;
¡P Copper;
¡P Lead;
¡P Mercury
¡P Nickel;
¡P Silver;
¡P Zinc;
¡P Total Polychlorinated Biphenyls
(PCBs);
¡P Organochlorine Pesticides (DDE & DDT);
¡P Tributyltin (TBT);
¡P Polycyclic Aromatic Hydrocarbons
(PAHs); and,
¡P Moisture content.
For each of the
target taxon a total of five replicates (i.e. composite samples) from each station
should be analysed for each analytical parameter for tissue and whole body
analysis, respectively. The number
of replicates is the same as those currently proposed for the CMP V EM&A
programme and will initially be used for SB monitoring as a consistent and
conservative approach. It will be
reviewed and adjusted accordingly based on power analyses in each Annual Review Report.
In
the event when insufficient biota are collected in the trawl samples for
chemical analysis of contaminants.
Samples may be pooled using the procedures shown in Table 6.3 and in the text below. It may be noted that inter-seasonal
pooling is not permitted.
Table 6.3 Methodology
for Pooling Samples to Obtain Sufficient Tissue/Whole Body
# |
Step Stations to Be
Combined |
Decision Criteria |
1 |
Impact
(INA) + Impact (INB) = Impact Reference
(TNA) + Reference (TNB) = Reference |
Proceed
to step 2 unless tissue and whole
body samples are adequate for
analysis |
2 |
Above
+ previous months Impact (INA) = Impact Above
+ Reference (TSA) + Reference (TSB) = Reference |
Proceed
to step 3 unless Proceed to step
2 unless tissue and whole body samples
are adequate for analysis |
3 |
Above
+ previous months Impact (INB) = Impact Above
+ previous months Reference (TNA) = Reference |
Proceed
to step 4 unless Proceed to step
2 unless tissue and whole body samples
are adequate for analysis |
4 |
Above
+ previous months Reference (TSB) = Reference |
Proceed
to step 5 unless Proceed to step
2 unless tissue and whole body samples are adequate for analysis |
5 |
Above
+ Reference (TSA) and Reference (TSB) = Reference |
N/A |
(1)
Note that inter-seasonal pooling is not permitted
The
pooling of Reference and Impact biota is not permitted. Pooling biota from station in the same
area should only be done as a last measure.
Wherever
possible, samples from the same station and of the same species should be
pooled together ie pooling together Species X from
TNA Trawl 1 January 2012 with TNA Trawl 2 January 2012 would be preferable to
pooling samples from TNA and TNB, this can sometimes be unavoidable due to low
catch rates. Pooling of totally
different taxa is not permitted, however, similar taxa
can sometimes be pooled when using ¡¥Alternative Species¡¦.
If
insufficient material is obtained following pooling then, material should be
kept and used in ¡¥Alternative Species¡¦ pooling if they are of a similar group
(e.g. if not enough Charybdis cruciata are available after the pooling of stations it
is possible to pool with other Charybdis sp.). Contaminant uptake is dependent on the
salinity of the water, which is seasonal.
Typically greater uptake occurs during the wet season when salinity is
lower than in the dry season ([20]).
For this reason, the pooling of samples between different seasons should
not be conducted.
Catches
from the trawl vessel should be processed to record the abundance and biomass
of individuals of commercial fisheries resources as well as the number of
species (or to the lowest possible taxonomic level) present.
Trawl
sampling should be conducted during daytime (0600 ¡V 1800 hours) by a shrimp
trawler equipped with a GPS system to ensure accurate positioning of each
trawl. Five replicate trawls, with
six nets deployed in each, should be conducted for 10 minutes at a trawl speed
of about 5 km/hr at each station.
If more than one of the six nets are retrieved
in a damaged condition, the samples should be rejected and the trawl
repeated. To ensure the quality of
the benthic trawl samples, several control measures have been incorporated into
the sampling programme, including:
¡P no more than three consecutive trawls
should be conducted at a station and resampling should only occur after a
minimum of two hours has elapsed;
¡P subsequent trawls at each station
should be shifted (e.g. by ~ 500 m) to avoid repetitive sampling over the same
area of seabed; and,
¡P the first station sampled in each survey
should be selected at random to minimise the diurnal influences on catches.
Catches
from all six nets in each trawl should be combined to form one sample. Each sample should be immediately washed
and stored in sterilised (with hexane) glass jars. All samples should be chilled to 4 ¢XC and transported to the laboratory
for further sorting and analysis.
The
waters north of Lantau have historically been important fishing grounds. These fishermen's catches comprise
mainly shrimps and crabs, as well as fish species of relatively low commercial
value such as pony fish, puffer fish and gobies ([21]).
The North of Lantau area also is recognized as the primary habitat of
the Indo-Pacific Humpback Dolphin (Sousa chinensis) within
Backfilling
operations at the SB Facility will be designed to minimize the dispersion of
contaminated sediments during disposal and to prevent the long-term migration
of contaminants through placement of a clean sand and mud cap. However, as losses of contaminated
sediment will nevertheless occur during placement, and as the area serves as
habitat for marine species which may be consumed by humans and/or the
Indo-Pacific Humpback Dolphin, the risk of adverse impacts must be addressed by
the monitoring programme. Pathways
of contaminant release to sensitive receivers (ie
humans and dolphins) include ingestion of contaminated sediment, ingestion of
dissolved and suspended contaminants in water, and ingestion of organisms with
contaminant residues.
Consequently,
a risk assessment will be performed on an annual basis to verify that no
unacceptable risk are occurring to either human health or marine mammals as a
result of consuming prey species from the waters in the vicinity of the pits of
North Lantau. The details of the
EM&A programme for assessing hazard to health of humans and marine mammals
are presented below.
The
objective of the risk assessment component of the monitoring programme is to
determine whether backfilling operations at the active pits are posing an
unacceptable risk to humans and dolphins through consumption of seafood/marine
prey species from the
Given
the above discussion of objectives, the impact hypotheses for this component of
the monitoring programme are defined as follows:
For Human Health
IH1:
Risks to human health from consumption of
commercial species captured adjacent to the active pits are no greater than
risks associated with consumption of species remote from the active pits;
AND
IH2:
Risks
to human health from consumption of commercial species captured adjacent to the
active pits are below the screening risk criterion (see Section 7.5).
For
Dolphins
IH1: Risks
to dolphins from consumption of prey species captured adjacent to the active
pits are no greater than risks associated with consumption of prey species
remote from the active pits;
AND
IH2: Risks
to dolphins from consumption of prey species captured adjacent to the active
pits are below the screening risk criterion (see Section 7.5).
Data
required for the risk assessment should consist of:
¡P contaminant concentrations in
commercial/prey species collected from stations adjacent to and remote from the
active pits;
¡P toxicology data for humans and
dolphins;
¡P literature-derived human consumption
rates and patterns for seafood;
¡P literature-derived data on exposure of
humans from other food groups;
¡P literature-derived data on contaminant
levels in marine mammals;
¡P data collected by AFCD on contaminant
levels in stranded Sousa chinensis carcasses; and,
¡P existing natural history information for the
Indo-Pacific Humpback Dolphin and related species (eg
diet composition and feeding range).
The
primary data input to the risk assessment should derive from the biannual trawl
(ie tissue samples for human populations and whole
body samples for dolphins) monitoring events (Section 6). The risk
assessment will be performed on an annual basis.
The
risk assessment will follow the guidelines of the US Environmental Protection
Agency ([22]) ([23])
and will incorporate a
four-step approach involving problem formulation, estimation of exposure,
characterization of ecological or human health effects (injury), and risk
characterization. Each of these
steps is described below with reference to how each applies to both human
health and ecological risk assessment.
Problem Formulation: Also known as hazard
definition ([24]), the problem formulation will
describe the sensitive populations (eg the general
Hong Kong population, subsistence fishermen, the Indo-Pacific Humpback Dolphin)
and identify biological effects of concern potentially associated with the
backfilling operations at the active facility. Identification of these effects should
include a discussion of contaminants of concern, measurement endpoints and a
conceptual model embodying the mechanisms of contaminant migration.
Estimation of Exposure: The purpose of the exposure
estimation is to determine the intake of each contaminant of concern by
potentially exposed individuals.
This step will consider the various routes of contaminant release and
their migration from the site to sensitive receivers. Factors such as fate and transport
processes, the concentrations in the ambient environment, and the maximum
short-term or average lifetime doses should be assessed.
For human populations exposure factors
presented in previous reports (1) (2) will be critically evaluated
to determine if further modification is necessary. These factors, which include amounts of
seafood consumed, origin of seafood products, and methods of preparation (eg raw versus cooked, whole body vs tissue only) will be
evaluated for the general population and any sensitive sub-populations (eg subsistence fishermen fishing in the SB area).
Characterization of
Effects: The effects
assessment is designed to quantify the relationship between the degree of
exposure to a substance and the extent of toxic injury or disease. This step in the assessment will use
data derived from dose response studies on laboratory animals or, less
frequently, on exposed human populations and clinical trials. For non-carcinogenic substances, once
the relationship between doses and responses is established, a threshold which
represents the highest contaminant concentration that is not expected to result
in an adverse effect, ie the reference dose (RfD) or a No Observed Adverse
Effect Level (NOAEL) can be established.
This threshold will then compare to the dose derived from the exposure
assessment above to produce the risk characterization.
For
humans, dose-response relationships must be considered separately for
carcinogens and non-carcinogens.
When dealing with carcinogens, a cancer potency factor (CPF) or Slope
Factor (SF) for each contaminant of concern will be used. For non-carcinogens, the NOAEL or LOAEL
(lowest observed adverse effect level) will be used as the threshold
value. Data on CPFs and NOAEL/LOAEL
values are available through the
Risk Characterization: The risk characterization will
integrate the results of the exposure and effects assessments to estimate the
risks and consequences of contaminant exposures. In this step, the estimated exposure
should be divided by the threshold value to obtain a Hazard Quotient (HQ). Generally HQ values below 1 are
considered to represent a very low risk of adverse effects, whereas HQ values
above 10 indicate a moderate to high level of risk.
For
human populations, the general approach to evaluating HQs can be applied to
this Project. However, the human
health risk characterization produced for this Project should be updated through
the use of continually collected tissue and other environmental monitoring data
to reflect current conditions. This
Study's human health risk assessment will improve the robustness of previous
studies through a careful reconsideration of all exposure and effects
parameters, with particular focus on background doses and seafood consumption
patterns.
The
EIA conducted for the SB Facility has indicated that benthic fauna are expected
to recolonise the pits following capping with
uncontaminated mud. It is expected
that recolonisation of the natural benthic assemblage
will occur and eventually the benthic assemblage will resemble that of the
surrounding areas. Recolonisation may be achieved by larval recruitment, influx
of juveniles or adults carried in water currents, or through the active
swimming or crawling of individuals.
However, other natural (eg storm events,
hypoxia, salinity fluctuations) or anthropogenic (eg
pollution, dredging activities and fisheries operations) activities may hinder recolonisation of capped pits. As a result, the factors contributing to
the composition of the benthic assemblage may be difficult to determine. It is also important for any recolonisation studies to be aware of any cap maintenance
(or "topping up") activities which may also impact the resident
benthic assemblages.
In
order to verify the recolonisation of marine biota on
the capped pits, a benthic recolonisation programme
is recommended. The full details of
the EM&A programme for benthic recolonisation are
presented in the following sections.
The
objective for this component of the EM&A is to monitor and report on the
benthic recolonisation of the capped pits including
the previous ones and specifically to determine the difference in infauna between the capped pits and adjacent sites.
The
impact hypothesis for this task is as follows:
Recolonisation
is occurring at the capped pits such that assemblages at the capped pits become
more similar to reference assemblages as time since capping increases.
The
null hypothesis to be tested for this work component is as follows:
H0
There is no difference in the
structure of benthic infaunal assemblages found at
the capped pits at the active facility and adjacent reference areas.
H0 Similarity of assemblage structures
between impact and reference stations does not change over time.
The
sampling design of this task involves two treatments: capped pits and reference
areas. The capped pit treatment
will involve collection of samples from the capped mud pits at the active
facility. The second treatment will
involve sampling at different reference sites, which are chosen to improve the
balanced nature of the design.
Using multiple controls is an effective way of ensuring that the
extremely variable nature of
The
benthic sediment samples collected during this task will be analysed for the
following parameters:
¡P Percentage of silt/clay in the
sediments;
¡P Faunal Abundance;
¡P Faunal Biomass;
¡P Species Composition; and,
¡P Trophic Structure
The
locations of impact and reference stations for the SB facility are shown in Figure 8.1 and the coordinates are shown Table 8.1. For standardisation purposes, the
reference stations are at the same locations as existing monitoring programmes
for ESC facilities. Samples will be
collected twice per year, once in the dry season, once during the wet
season. Twelve replicate samples
will be collected from each of the monitoring stations. Sampling will commence once capping of
all pits is completed, as detailed in the Sampling
Programme in Annex C.
The
sampling frequency and number of replicates are the same as those currently
proposed for the CMP IV/ V EM&A programmes and will initially be used for
SB monitoring as a consistent and conservative approach. These will be reviewed and adjusted
accordingly based on power analyses in each Annual
Review Report.
Table 8.1 Coordinates
of Benthic Monitoring Stations at South Brothers Facility
Station |
Easting |
Northing |
Reference |
|
|
RBA |
806399 |
821682 |
RBB |
808206 |
822708 |
RBC |
806171 |
819354 |
Capped Pit |
|
|
SB-CPA |
815231 |
819548 |
SB-CPB |
814808 |
819098 |
Note: Coordinates are based on
The
data collected during the monitoring programme will be analysed using two different
but complementary approaches as detailed below.
ANOVA
& MANOVA: Simple, univariate measures will be tested using an Analysis of
Variance (ANOVA), and multivariate measures of community structure will be
tested using the Multiple Analysis of Variance (MANOVA). Both ANOVA and MANOVA test the same null
hypothesis using similar methods.
The method is essentially a comparison of the variability within a site
to the variability between sites.
If the ratio of these two variances (that is, the between-group-variance
over the within-group-variance) is large enough, then any differences observed
are due to true differences that exist between the groups and not just to random variation.
ANOVA and MANOVA tests are based on several assumptions related to the
underlying distribution of the data being analysed (ie
normality, homogeneity of variances).
If the data deviate significantly from these assumptions, then these
tests are considered to be inappropriate.
If this situation arises, alternative procedures (ie
parametric tests with rank transformed data or non-parametric analogues such as
Kruskal Wallis) which address similar hypotheses but
do not require such stringent assumptions will be adopted. Observed differences between the sites
and/or areas will be tested using multiple comparison procedures such as the
Student Newman Keuls (SNK) or Tukey
test.
Non-metric
Multi-dimensional Scaling (MDS):
Multi-dimensional Scaling (MDS) will also be used to depict the similarities
between stations based on their benthic assemblages. MDS is a method for creating a low
dimensional picture of the relationships between stations in a complex,
multi-dimensional problem. The
Bray-Curtis distance matrices will be used for both the clustering techniques
and the MDS. The dendrogram from the cluster analysis and the MDS ordination
plot will provide complementary views of the same similarity information. The data for MDS and cluster analyses
should be standardised prior to analysis, to ensure that bias resulting from
including data in different forms (eg percent data
for silt clay composition, numerical data for abundances and biomass data in
mg) does not occur.
The
detailed statistical analyses described above will be used to comprehensively
explore the benthic assemblage patterns in the area of the active pits. This exploration should lead to
conclusions regarding the effectiveness of the cap material in promoting
post-dredging benthic assemblages.
The
sampling team and vessel will be deployed and accurate positioning attained as
described in Section 4. The vessel will be equipped with
adequate fixed sieve stations to facilitate rapid processing of samples and
ensure the required number of samples are collected in
each survey. At each of the
designated benthic sampling stations, seabed sampling will be carried out with
a modified Van Veen grab sampler (dimensions 30 cm H
30 cm H 15 cm D) or similar instrument approved by EPD/AFCD. One subsample of approximately 1 kg
sediment will be collected from each sample for analysis of particle size. The remaining sediment from each sample
will be used for sorting. Samples
will be labelled and sieved through a 1 mm and 0.5 mm sieve and all residues
and organisms retained, double-bagged and preserved in 4% buffered formalin in
seawater. A vital stain (eg Rose bengal)
will be added to distinguish organic materials and organisms from other
non-living residues. The grab and
utensils will be washed thoroughly with seawater after each deployment to avoid
cross-contamination between samples.
On completion of the survey all samples will be transferred to the
laboratory for sorting and identification.
All sediment sieving will be conducted by qualified marine scientists
who will oversee and coordinate all field operations.
Upon arrival at the laboratory, all
benthic samples should be re-inventoried and checked against chain-of-custody
forms. Sample rescreening should be
performed after the samples have been held in formalin for a minimum of 24
hours to ensure adequate fixation of the organisms. Individual samples from the 500 £gm and 1 mm2 mesh sieves will be gently rinsed
with fresh water into a 250 £gm sieve to remove the
formalin from the sediments. Sieves
will be partially filled while rinsing a specific sample to maximize washing
efficiency and prevent loss of material.
All material retained on the 250 £gm sieve is
placed in small fractions into a labelled petri dish and preserved with 70%
ethanol. The material is lightly
agitated to ensure complete mixing of the alcohol with the sediments. The sediment is then sorted to remove
all animals and fragments. Original
labels will remain with the rescreened sample material.
Standard
and accepted techniques will be used for sorting organisms from the
sediments ([27]).
Small fractions of a sample will be placed in a petri dish under a
10-power magnification dissecting microscope. The petri dish will be scanned
systematically and all animals and fragments removed using forceps. Each petri dish will be sorted at least
twice to ensure removal of all animals.
Organisms representing major taxonomic groups including Polychaeta, Arthropoda, Mollusca,
and miscellaneous taxa will be sorted into separate, labelled vials containing
70 percent ethanol. All sorted
samples will be systematically checked to ensure compliance with QA/QC program
requirements before proceeding to the taxonomic identification, enumeration,
and biomass determination phases of the analysis.
Taxonomic
identifications will be performed by regional taxonomic experts using stereo
dissecting and high-power compound microscopes, to the family level except for
dominants, which will be identified, where possible, to species. The careful sampling procedure employed
in the Study will minimise fragmentation of organisms, however should breakage
of soft-bodied organisms occur, only anterior portions
of organism fragments will be counted.
All fragments will be retained and weighed during biomass
determinations, described below.
Rare or questionable taxa will be compared against reference collection
specimens for confirmation and consistency of identification. The nomenclature used in all reference
collections referred to in this study should be cross checked and differences
or discrepancies should be noted.
Biomass determinations will be made by taking the blotted wet mass of
each taxonomic fraction.
Sorting
QA/QC will be performed using 25-power magnification by someone other than the
original sorter. Twenty percent of
each sorted sample should be resorted to ensure 95 percent sorting
efficiency. A sample passes QA/QC
if the number of organisms found during the QA/QC check does not represent more
than 5 percent of the total number of organisms found in the entire
sample. If the number of organisms
found is greater than 5 percent of the total number, the entire sample will be
resorted. Any samples where the
identification of taxa is questionable will be sent out for independent
re-identification by a qualified regional expert. Reference collections developed during
previous seabed and benthic studies in
Based
on the previous experience with the development and approval for CMPs at East
of Sha Chau for use as a contained aquatic disposal for contaminated sediment,
monitoring of the dispersion of uncapped sediments during major storm events,
such as typhoons of signal 8 or higher, is an important objective of this
EM&A programme. It is therefore
considered necessary to include this post-storm monitoring as part of the
EM&A programme when the SB Facility is active for backfilling operations.
The
post-storm monitoring programme will mobilise within one week of a major storm
event (Typhoon Signal Number 8 or above) in order to determine whether the pits
retain disposed sediments during storms and whether there are any detectable
changes in sediment quality adjacent to the pits. Sediment samples will be collected
within one week of a major storm at stations of the Cumulative Impact Monitoring of Sediment Quality programme (Figure 4.2; Section
4.4.3). Only inorganic
contaminants and particle size distribution (organic contaminants are not
measured as inorganics can provide a more cost-effective indicator of any
sediment quality change) will be analysed in the storm assessment.
The
field, laboratory and QA/QC procedures for sediment sample collection after
major storm events will be identical to those used for the Cumulative Impact Monitoring of Sediment Quality Programme (Section 4).
Reports
will be provided in both hard copy and electronic version upon agreeing the
format with EPD. This would enable
a transition from a paper/historic and reactive approach to an electronic/real
time proactive approach.
The
following documents will be submitted as part of the EM&A programme:
¡P Environmental Monitoring and Audit
Manual;
¡P Reports on Dredging and Capping
Operations;
¡P Monthly EM&A Reports;
¡P Quarterly EM&A Reports;
¡P Annual Review Report;
¡P Annual Risk Assessment Report;
¡P Draft Final EM&A Report;
¡P Executive Summary Report; and
¡P Final EM&A Report.
Monthly EM&A Reports will be required for the duration of
the programme period and will be submitted to CEDD by the 10th working day of
each month. Each report will
typically contain:
¡P a list of the activities, tests,
analyses and assessments performed in the month according to that detailed in the
Environmental Monitoring and Audit Manual for the purpose of reporting any
significant findings resulting from monitoring and audit activities;
¡P a list of outstanding activities,
tests, analyses and assessments as well as the schedule for completing these
outstanding items; and,
¡P a list of previously outstanding
activities, tests, analyses and assessments that are completed in the month.
Quarterly EM&A Reports will be required for the duration of the
programme period and will be submitted within 30 days from the end of every
quarterly monitoring period. Each
report will:
¡P confirm that all activities, tests, analyses,
assessments etc. have been carried
out as stated in this EM&A Manual;
¡P report on the auditor's findings on
the field events and laboratory tests and analysis;
¡P report on any trends resulting from
disposal, dredging and capping activities at the active facility.
An Annual Review Report will be submitted
within 60 days from the end of every yearly monitoring period. Each report will:
¡P make a clear statement on the
acceptability of environmental impacts by reference to the impact hypotheses;
¡P state how successful the monitoring
programme has been in addressing the objectives of the Assignment;
¡P make recommendations for revisions to
the monitoring programme and disposal operation, as necessary, to ensure that
the objectives are fully met in a cost effective manner; and
¡P summarise the monitoring results to illustrate
whether any change or trend resulting from the disposal, dredging and capping
activities is detected or not.
A Risk Assessment Report will be prepared within 60 days from
the end of every yearly monitoring period.
Each report will address the risk to the human health and dolphin of eating
seafood taken in the marine area around
A Draft Final EM&A Report will be prepared within 90 days from
the end of the monitoring period for this EM&A programme. It will address how each objective of
the EM&A programme has been met and should will include a final version of
the EM&A Manual as an appendix.
A Final EM&A Report will be prepared within 3 weeks after the agreed
revisions on the Draft Final Report.
An English and
Chinese Executive Summary Report
will be prepared within 3 weeks of receipt of comments on the Draft Final
Report. It should highlight any
issues of concern and the acceptability of the operations at the SB facility.
([1])
According
to the Management Framework of Dredged/ Excavated Sediment of ETWB TC(W) No.
34/2002, contaminated sediment in general shall mean those sediment requiring Type
2 ¡V Confined Marine Disposal as determined according to this TC(W).
([2]) CAD
options may involve use of excavated borrow pits, or
may involve purpose-built excavated pits.
CAD sites are those which involve filling a seabed pit with contaminated
mud and capping it with uncontaminated material such that the original seabed
level is restored and the contaminated material is isolated from the
surrounding marine environment.
([3])
Detailed
Site Selection Study for a Proposed Contaminated Mud Disposal Facility within
the Airport East/ East of Sha Chau Area (Agreement No. CE 12/2002(EP))
([4])
Under the
CEDD study Contaminated Sediment Disposal
Facility to the South of The Brothers (Agreement No. FM 2/2009)
([5])
The EIA
Report for New Contaminated Mud Marine
Disposal Facility at Airport East / East Sha Chau Area was prepared under
the CEDD consultancy Detailed Site
Selection Study for a Proposed Contaminated Mud Disposal Facility within the
Airport East/ East of Sha Chau Area (Agreement No. CE 12/2002(EP))
([6])
It is
proposed that impact monitoring data from individual downstream stations will
be compared against the average of data from upstream stations on the same
monitoring day.
([7]) ERM
(2014). 6th
Quarterly Report for Contaminated Mud Pits to the South of The
Brothers and at East Sha Chau ¡V December 2013 to February 2014. Submitted to EPD.
([8])
It is
proposed that impact monitoring data from individual downstream stations will
be compared against the average of data from upstream stations on the same
monitoring day.
([9])
Should
consistent exceedance of the Action & Limit Levels for the stated
parameters are detected at bottom level, such monitoring may be extended to
other parameters.
([10])
It is proposed that
impact monitoring data from individual downstream stations will be compared
against the average of data from upstream stations on the same monitoring day.
([13])
AJ Underwood (1997)
Experiments in Ecology: their logical design and interpretation using analysis
of variance.
([14])
Puget Sound Estuary
Program (PSEP) (1995). Recommended guidelines for conducting laboratory bioassays on Puget
Sound sediments. Prepared for the US EPA.
([15])
U.S.EPA (U.S. Environmental
Protection Agency) (1994). Methods for assessing the toxicity of sediment-associated
contaminants with estuarine and marine amphipods. Office of Research and
Development. U.S. Environmental
Protection Agency, Cincinnati, OH.
([16])
EVS (1996). Testing of
Dredged material for Marine Disposal: Environmental Laboratory Guidance
Document. Prepared for CED.
([17])
EVS (1996). Testing of
Dredged material for Marine Disposal: Environmental Laboratory Guidance
Document. Prepared for CED.
([21])
ERM (1997) Fisheries
Resources and Fishing Operations in Hong Kong Waters. Draft Final Report prepared
AFD.
([22])
U.S. Environmental
Protection Agency.
1992. Framework for
Ecological Risk Assessment. EPA/630/R-92/001.
Risk Assessment Forum, U.S. EPA, Washington, DC.
([23])
U.S. Environmental
Protection Agency.
1996. Ecological Risk
Assessment Guidance for Superfund: Process for Designing and Conducting
Ecological Risk Assessments (Draft).
U.S. EPA.